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We investigate nonlinear energy transfer for channel flows at friction Reynolds numbers $Re_{\tau }=180$ and $590$. The key feature of the analysis is that we quantify the energy transferred from a source mode to a recipient mode, with each mode characterised by a streamwise wavenumber and a spanwise wavenumber. This is achieved through an explicit examination of the triadic interactions of the nonlinear energy transfer term in the spectral turbulent kinetic energy equation. First, we quantify the nonlinear energy transfer gain and loss for individual Fourier modes. The gain and loss cannot be obtained without expanding the nonlinear triadic interactions. Second, we quantify the nonlinear energy transfer budgets for three types of modes. Each type of mode is characterised by a specific region in streamwise–spanwise wavenumber space. We find that a transverse cascade from streamwise-elongated modes to spanwise-elongated modes exists for all three types of modes. Third, we quantify the forward and inverse cascades between resolved scales and subgrid scales in the spirit of large-eddy simulations. For the cutoff wavelength range that we consider, the forward and inverse cascades between the resolved scales and subgrid scales result in a net forward cascade from the resolved scales to the subgrid scales. The shape of the net forward cascade curve with respect to the cutoff wavelength resembles the net forward cascade predicted by the Smagorinsky eddy viscosity.
This study examined children at the onset of tic disorder (tics for less than 9 months: NT group), a population on which little research exists. Here, we investigate relationships between the baseline shape and volume of subcortical nuclei, diagnosis, and tic symptom outcomes.
Methods
187 children were assessed at baseline and a 12-month follow-up: 88 with NT, 60 tic-free healthy controls (HC), and 39 with chronic tic disorder/Tourette syndrome (TS), using T1-weighted MRI and total tic scores (TTS) from the Yale Global Tic Severity Scale to evaluate symptom change. Subcortical surface maps were generated using FreeSurfer-initialized large deformation diffeomorphic metric mapping. Linear regression models correlated baseline structural shapes with follow-up TTS while accounting for covariates, with relationships mapped onto structure surfaces.
Results
We found that the NT group had a larger right hippocampus compared to HC. Surface maps illustrate distinct patterns of inward deformation in the putamen and outward deformation in the thalamus for NT compared to controls. We also found patterns of outward deformation in almost all studied structures when comparing the TS group to controls. The NT group also showed consistent outward deformation compared to TS in the caudate, accumbens, putamen, and thalamus. Subsequent analyses including clinical symptoms revealed that a larger pallidum and thalamus at baseline correlated with less improvement of tic symptoms at follow-up.
Conclusion
These observations constitute some of the first prognostic biomarkers for tic disorders and suggest that these subregional shape and volume differences may be associated with the outcome of tic disorders.
Humans depend heavily on nature. Drylands are home to 2.5 billion people, but the extent to which nature contributes to people (NCP) in drylands has been little explored. We examined the global contribution of nature to people, aiming to compare drylands and non-drylands. We predicted a lower contribution in drylands than non-drylands, largely because of the sparser population densities (peoples’ needs) and more degraded status of natural resources (lower potential contribution). Consistent with expectation, nature’s contribution was about 30% lower in drylands, with significantly lower values for drylands in Asia, Oceania, Africa and South America, but no difference for Europe and North America. Differences were due mainly to lower contributions from material and regulating contributions, i.e., the regulation of air quality, climate, water quantity and flow, soil protection and the supply of woody material, and potentially, lower use by people in drylands. Predicted declines in rainfall and increasing temperature are likely to place increasing pressure on nature to contribute to human well-being in drylands. A better understanding of nature’s contributions to people would improve our ability to allocate limited resources and achieve sustainable development in drylands.
The poor environmental stability of natural anthocyanin hinders its usefulness in various functional applications. The objectives of the present study were to enhance the environmental stability of anthocyanin extracted from Lycium ruthenicum by mixing it with montmorillonite to form an organic/inorganic hybrid pigment, and then to synthesize allochroic biodegradable composite films by incorporating the hybrid pigment into sodium alginate and test them for potential applications in food testing and packaging. The results of X-ray diffraction, Fourier-transform infrared spectroscopy, and use of the Brunauer–Emmett–Teller method and zeta potential demonstrated that anthocyanin was both adsorbed on the surface and intercalated into the interlayer of montmorillonite via host–guest interaction, and the hybrid pigments obtained allowed good, reversible, acid/base behavior after exposure to HCl and NH3 atmospheres. The composite films containing hybrid pigments had good mechanical properties due to the uniform dispersion of the pigments in a sodium alginate substrate and the formation of hydrogen bonds between them. Interestingly, the composite films also exhibited reversible acidichromism. The as-prepared hybrid pigments in composite films could, therefore, serve simultaneously as a reinforced material and as a smart coloring agent for a polymer substrate.
Despite a substantial epidemiological literature on the incidence of psychotic disorders in Ireland, no systematic review has previously been undertaken. Such evidence can help inform understanding of need for psychosis care.
Methods:
We conducted a prospectively registered systematic review (PROSPERO: CRD42021245891) following PRISMA guidelines. We searched four databases (Medline, PsycInfo, Web of Science, Embase) for papers containing incidence data on non-organic psychotic disorders, in people 16–64 years, published between 1950 and 2021 in the general adult population. We conducted duplicate screening, risk of bias assessments, and extracted data to a standardised template. We undertook a narrative synthesis for each major diagnostic outcome. Random effects meta-analyses were conducted for comparisons with ≥5 incidence rates.
Results:
Our search yielded 1975 non-duplicate citations, of which 23 met inclusion criteria, containing incidence data ascertained between 1974 and 2016 (median study quality: 5/8; interquartile range: 4–6). Incidence of all psychotic disorders (N = 4 studies) varied from 22.0 (95%CI: 17.3–28.0) in Dublin to 34.1 per 100,000 person-years (95%CI: 31.0–37.5) in Cavan and Monaghan. The pooled incidence of schizophrenia (N = 6 studies, N = 8 settings) was 20.0 per 100,000 person-years, though with imprecision around this estimate (95%CI: 10.6–37.5; I2: 97.6%). Higher rates of most outcomes were observed in men. There was consistent evidence of raised rates in more deprived and fragmented social environments, but no clear pattern by rural-urban status.
Conclusions:
Patterns of incidence of psychotic disorders in Ireland are broadly consistent with the wider literature from the Global North. Findings could help identify populations at higher risk of psychosis in Ireland.
The target backsheath field acceleration mechanism is one of the main mechanisms of laser-driven proton acceleration (LDPA) and strongly depends on the comprehensive performance of the ultrashort ultra-intense lasers used as the driving sources. The successful use of the SG-II Peta-watt (SG-II PW) laser facility for LDPA and its applications in radiographic diagnoses have been manifested by the good performance of the SG-II PW facility. Recently, the SG-II PW laser facility has undergone extensive maintenance and a comprehensive technical upgrade in terms of the seed source, laser contrast and terminal focus. LDPA experiments were performed using the maintained SG-II PW laser beam, and the highest cutoff energy of the proton beam was obviously increased. Accordingly, a double-film target structure was used, and the maximum cutoff energy of the proton beam was up to 70 MeV. These results demonstrate that the comprehensive performance of the SG-II PW laser facility was improved significantly.
OBJECTIVES/GOALS: Smoking is a well-established risk factor for lung cancer, but never smokers account for up to 25% of lung cancer cases. There is mounting evidence that lung cancer in never smokers is biologically distinct. We aim to characterize the genomic and immunologic features of lung adenocarcinoma in never smokers versus smokers. METHODS/STUDY POPULATION: We examined clinical, genomic, and bulk-RNA sequencing data from 499 patients in the TCGA lung adenocarcinoma cohort. Tumor mutation burden was analyzed using maftools (R package). Tumor immune characterization was completed using CIBERSORTx, a digital cytometry tool that uses single cell reference profiles to determine immune cell type frequencies from bulk-RNA sequencing data. Single cell reference profiles for 19 different immune cell types were constructed from sequencing of freshly resected lung tumor tissue from UCSF patients. Partitioning Around Medoids (PAM; R package) was used to identify distinct immune phenotypes based on immune cell composition. Fisher’s exact test was used to evaluate for associations between immune phenotypes and smoking status. RESULTS/ANTICIPATED RESULTS: Of the 499 TCGA lung adenocarcinoma patients, 75 were never smokers, 269 were female, and 246 were over the age of 65. Never smokers had lower tumor mutation burden and lower predicted neoantigen burden compared to smokers (p < 0.001). There was no difference in total tumor immune cell infiltration between never smokers and smokers. PAM yielded 2 distinct clusters/immune phenotypes. The first was enriched in M1 Macrophages, cytotoxic T Cells, helper T Cells, regulatory T Cells, and Plasma Cells. The second was enriched in plasmacytoid Dendritic Cells, M2 Macrophages, and exhausted cytotoxic T Cells. Never smoking status was associated with an increased odds of having the first immune phenotype (OR 1.95, 95% CI: 1.15 - 3.35) and this association was statistically significant (p = 0.0086). DISCUSSION/SIGNIFICANCE: Our findings suggest that never smokers have an immune phenotype that is distinct from that observed in smokers. The distinct immune characteristics we observed could explain clinical trial data suggesting immune checkpoint inhibitors are less effective in never smokers and hold implications for tailoring therapy.
This study aimed to establish a model for predicting the three-year survival status of patients with hypopharyngeal squamous cell carcinoma using artificial intelligence algorithms.
Method
Data from 295 patients with hypopharyngeal squamous cell carcinoma were analysed retrospectively. Training sets comprised 70 per cent of the data and test sets the remaining 30 per cent. A total of 22 clinical parameters were included as training features. In total, 12 different types of machine learning algorithms were used for model construction. Accuracy, sensitivity, specificity, area under the receiver operating characteristic curve and Cohen's kappa co-efficient were used to evaluate model performance.
Results
The XGBoost algorithm achieved the best model performance. Accuracy, sensitivity, specificity, area under the receiver operating characteristic curve and kappa value of the model were 80.9 per cent, 92.6 per cent, 62.9 per cent, 77.7 per cent and 58.1 per cent, respectively.
Conclusion
This study successfully identified a machine learning model for predicting three-year survival status for patients with hypopharyngeal squamous cell carcinoma that can offer a new prognostic evaluation method for the clinical treatment of these patients.
Energy drinks are consumed for a variety of reasons, including to boost mental alertness and energy. We assessed associations between demographic factors and various high-risky behaviours with energy drink consumption as they may be linked to adverse health events.
Design:
We conducted cross-sectional analysis including basic descriptive and multivariable-adjusted logistic regression analyses to characterise demographic and behavioural factors (including diet quality, binge drinking and illicit drug use, among others obtained via questionnaires) in relation to energy drink consumption.
Setting:
We used data from two large US-based cohorts.
Participants:
46 390 participants from Nurses’ Health Study 3 (NHS3, n 37 302; ages 16–31) and Growing Up Today Study (GUTS, n 9088, ages 20–55).
Results:
Of the 46 390 participants, 13·2 % reported consuming ≥ 1 energy drink every month. Several risky behaviours were associated with energy drink use, including illegal drug use (pooled OR, pOR: 1·45, 95 % CI: 1·16, 1·81), marijuana use (pOR: 1·49, 95 % CI: 1·28, 1·73), smoking (pOR: 1·88. 95 % CI: 1·55, 2·29), tanning bed use (pOR: 2·31, 95 % CI: 1·96, 2·72) and binge drinking (pOR: 2·53, 95 % CI: 2·09, 3·07). Other factors, such as high BMI, e-cigarette use and poor diet quality were found to be significantly associated with higher energy drink consumption (P values < 0·001).
Conclusions:
Our findings show that energy drink consumption and high-risk behaviours may be related, which could potentially serve as not only as a talking point for providers to address in outreach and communications with patients, but also a warning sign for medical and other health practitioners.
Vortical impulse theory is used to investigate the relationship between turbine thrust and the near-wake velocity and vorticity fields. Three different hypotheses regarding the near-wake structure allow the derivation of novel expressions for the thrust on a steadily rotating wind turbine, and these are tested using stereoscopic particle-image velocimetry (PIV) data acquired just behind a rotor in a water channel. When one assumes that vortex lines and streamlines are aligned in a rotor-fixed frame of reference, one obtains a PIV-based thrust estimate that fails even to capture the trend of the directly measured thrust, and this failure is attributed to an implicit assumption that most of the generated thrust does useful work. When one neglects the axial gradients of radial velocity, the PIV-based thrust estimate captures the measured thrust trend, but underpredicts its magnitude by approximately $33\,\%$. The third and most promising physical proposition treats the trailing vortices as purely ‘rolling’ structures that exhibit zero-strain rate in their cores, with the corresponding thrust estimates in close agreement with direct thrust measurements. This best-performing expression appears as a correction to the classical thrust expression from momentum theory, possessing additional squared-velocity terms that can account for the high-thrust regime of turbine operation that is typically addressed empirically.
The great demographic pressure brings tremendous volume of beef demand. The key to solve this problem is the growth and development of Chinese cattle. In order to find molecular markers conducive to the growth and development of Chinese cattle, sequencing was used to determine the position of copy number variations (CNVs), bioinformatics analysis was used to predict the function of ZNF146 gene, real-time fluorescent quantitative polymerase chain reaction (qPCR) was used for CNV genotyping and one-way analysis of variance was used for association analysis. The results showed that there exists CNV in Chr 18: 47225201-47229600 (5.0.1 version) of ZNF146 gene through the early sequencing results in the laboratory and predicted ZNF146 gene was expressed in liver, skeletal muscle and breast cells, and was amplified or overexpressed in pancreatic cancer, which promoted the development of tumour through bioinformatics. Therefore, it is predicted that ZNF146 gene affects the proliferation of muscle cells, and then affects the growth and development of cattle. Furthermore, CNV genotyping of ZNF146 gene was three types (deletion type, normal type and duplication type) by Real-time fluorescent quantitative PCR (qPCR). The association analysis results showed that ZNF146-CNV was significantly correlated with rump length of Qinchuan cattle, hucklebone width of Jiaxian red cattle and heart girth of Yunling cattle. From the above results, ZNF146-CNV had a significant effect on growth traits, which provided an important candidate molecular marker for growth and development of Chinese cattle.
Steinernema populi n. sp. was recovered by baiting from beneath poplar trees in China. Morphological and molecular features provided evidence for placing the new species into the Kushidai clade. The new species is characterized by the following morphological features: third-stage infective juveniles (IJ) with a body length of 1095 (973–1172) μm, a distance from the anterior end to excretory pore of 77 (70–86) μm and a tail length of 64 (55–72) μm. The Body length/Tail length (c) ratio and Anterior end to Excretory pore/ Tail length × 100 (E%) of S. populi n. sp. are substantially greater than those of all other ‘Feltiae–Kushidai–Monticolum’ group members. The first-generation males can be recognized by a spicule length of 66 (57–77) μm and a gubernaculum length of 46 (38–60) μm. The new species is further characterized by sequences of the internal transcribed spacer and partial 28S regions of the ribosomal DNA. Phylogenetic analyses show that Steinernema akhursti and Steinernema kushidai are the closest relatives to S. populi n. sp.
Sleep disturbance is an important factor in the pathophysiology and progression of psychiatric disorders, but whether it is a cause, or a downstream effect is still not clear.
Methods
To investigate causal relationships between three sleep-associated traits and seven psychiatric diseases, we used genetic variants related to insomnia, chronotype and sleep duration to perform a two-sample bidirectional Mendelian randomisation analysis. Summary-level data on psychiatric disorders were extracted from the Psychiatric Genomics Consortium. Effect estimates were obtained by using the inverse-variance-weighted (IVW), weights modified IVW, weighted-median methods, MR-Egger regression, MR pleiotropy residual sum and outlier (MR-PRESSO) test and Robust Adjusted Profile Score (RAPS).
Results
The causal odds ratio (OR) estimate of genetically determined insomnia was 1.33 (95% confidence interval (CI) 1.22–1.45; p = 5.03 × 10−11) for attention-deficit/hyperactivity disorder (ADHD), 1.31 (95% CI 1.25–1.37; p = 6.88 × 10−31) for major depressive disorder (MDD) and 1.32 (95% CI 1.23–1.40; p = 1.42 × 10−16) for post-traumatic stress disorder (PTSD). There were suggestive inverse associations of morningness chronotype with risk of MDD and schizophrenia (SCZ). Genetically predicted sleep duration was also nominally associated with the risk of bipolar disorder (BD). Conversely, PTSD and MDD were associated with an increased risk of insomnia (OR = 1.06, 95% CI 1.03–1.10, p = 7.85 × 10−4 for PTSD; OR = 1.37, 95% CI 1.14–1.64; p = 0.001 for MDD). A suggestive inverse association of ADHD and MDD with sleep duration was also observed.
Conclusions
Our findings provide evidence of potential causal relationships between sleep disturbance and psychiatric disorders. This suggests that abnormal sleep patterns may serve as markers for psychiatric disorders and offer opportunities for prevention and management in psychiatric disorders.
The objective of this study was to evaluate the efficacy of anti-reflux therapy on the idiopathic vocal process granulomas.
Method
This was a prospective case series study. The patients with vocal process granulomas who met the inclusion criteria were analysed. Proton pump inhibitors and vocal hygiene education were conducted for 8–20 weeks.
Results
Of the 16 patients with vocal process granulomas, 5 (31.25 per cent) patients achieved complete remission. The complete remission rate of granulomas was not significantly related to age (p = 1.000), sex (p = 0.296), side (p = 0.299), position (p = 0.100), endoscopic morphology (p = 0.263) or proton pump inhibitor treatment course (p = 0.543) but was significantly associated with granuloma location (p = 0.001) and granuloma size (p = 0.012).
Conclusion
Granulomas in the vocal cord and the margin of the vocal process had an excellent response to proton pump inhibitors, but granulomas on the surface of vocal process and arytenoid cartilage body had little response to proton pump inhibitors. The prolonged period of proton pump inhibitor treatment did not increase the complete remission rate of vocal process granulomas.
Intraventricular lesions are challenging pathologies in neurosurgery. Walter Dandy had a major impact in advancing our understanding of the management of these lesions. Furthermore, the introduction of the microscope and microsurgical techniques have improved the surgical outcomes of these lesions. Several approaches have been described to address ventricular lesions, and can be classified anatomically as anterior, lateral, or posterior. The operative corridor for each of these approaches transgresses unaffected neural tissues. Therefore, tailoring the approach to individual patient lesion characteristics and anatomy is crucial to maximize exposure and minimize morbidity. The majority of open and endoscopic approaches to the third ventricle use the interhemispheric anterior transcallosal, frontal transsulcal, or frontal transcortical corridor to access the lateral ventricle. Once inside the lateral ventricle, the operative corridors to the third ventricle include working through the foramen of Monroe (transforaminal approach) for small lesions located in the anterior superior part of the third ventricle, or through the choroidal fissure (transchoroidal or subchoroidal) which provide access to lesions located in, or extending into, the middle or posterior parts of the roof of the third ventricle. In this chapter, we will discuss the transchoroidal, subchoroidal, and combined transchoroidal and subchoroidal approaches to the third ventricle.
South-east Asia's diverse coastal wetlands, which span natural mudflats and mangroves to man-made salt pans, offer critical habitat for many migratory waterbird species in the East Asian–Australasian Flyway. Species dependent on these wetlands include nearly the entire population of the Critically Endangered spoon-billed sandpiper Calidris pygmaea and the Endangered spotted greenshank Tringa guttifer, and significant populations of several other globally threatened and declining species. Presently, more than 50 coastal Important Bird and Biodiversity Areas (IBAs) in the region (7.4% of all South-east Asian IBAs) support at least one threatened migratory species. However, recent studies continue to reveal major knowledge gaps on the distribution of migratory waterbirds and important wetland sites along South-east Asia's vast coastline, including undiscovered and potential IBAs. Alongside this, there are critical gaps in the representation of coastal wetlands across the protected area networks of many countries in this region (e.g. Viet Nam, Indonesia, Malaysia), hindering effective conservation. Although a better understanding of the value of coastal wetlands to people and their importance to migratory species is necessary, governments and other stakeholders need to do more to strengthen the conservation of these ecosystems by improving protected area coverage, habitat restoration, and coastal governance and management. This must be underpinned by the judicious use of evidence-based approaches, including satellite-tracking of migratory birds, ecological research and ground surveys.
Depression (MDD) is a serious mental illness, which greatly affects the quality of life of patients. Nowadays, the clinical diagnosis of MDD lacks sufficient objective basis, and the effect of drug treatment is unsatisfactory. Therefore, biomarkers are very important for the risk prediction, classification, diagnosis and prognosis of MDD.
Objectives
Research progress of metabonomics of blood endogenous small molecules in depression
Methods
Metabonomics is a newly developed discipline after genomics and proteomics, and is an important part of system biology. Metabonomics provides a new approach to explore the etiology, mechanism, prognosis and screening potential biomarkers of MDD. Blood contains almost all the small molecule metabolites in the body. The changes of metabolites in blood can represent the changes of metabolites in other body fluids. Moreover, this sample is easy to obtain and has less trauma, so it is the most common biological sample in clinical detection.
Results
At present, there are many studies on the metabonomics of endogenous small molecules in MDD blood, which provides the possibility for further screening of MDD related biomarkers.
Conclusions
In this paper, the research progress of related biomarkers in MDD blood is reviewed.
The relaxation of turbulent pipe flow downstream of a single square bar roughness element is studied at distances up to $120R$ ($R$ is the pipe radius). Three bar heights, $h/R = 0.04$, 0.1 and 0.2, are investigated. The data suggest three stages for the relaxing flow. Immediately following the square bar is the development of a separated shear layer, where we find that the peak Reynolds stress scales linearly with $h/R$ and the disturbance profile is characterised by $h$. The bulk shear stress and turbulence intensity in this stage scale as $(h/R)^{2}$ and reach their maximum near the reattachment point. The second stage features the redistribution of turbulence towards the pipe centre and a power law in the decay of turbulence. The extent of this region is characterised by a streamwise length scale, ${x_c}$, which measures the extent of the redistribution process. The final stage of recovery is found to be long-lasting and oscillatory owing to asynchronous recovery between the mean velocity and the Reynolds stress. The oscillation wavelength scales with ${x_c}$ and decreases with increasing $h/R$. In contrast, the deficits in the mean shear and the bulk shear stress increase with $h/R$. For all three bar sizes, the flow recovery is not complete until the streamwise distance exceeds 500$h$–1000$h$.
The function and change of global soil carbon (C) reserves in natural ecosystems are key regulators of future carbon-climate coupling. Microbes play a critical role in soil carbon cycling and yet there is poor understanding of their roles and C metabolism flexibility in many ecosystems. We wanted to determine whether vegetation type and climate zone influence soil microbial community composition (fungi and bacteria) and carbon resource preference. We used a biomarker (phospholipid fatty acids, PLFAs), natural abundance 13C and 14C probing approach to measure soil microbial composition and C resource use, along a 1900–4167-m elevation gradient on Mount Gongga (7556 m asl), China. Mount Gongga has a vertical mean annual temperature gradient of 1.2–10.1°C and a diversity of typical vegetation zones in the Tibetan Plateau. Soils were sampled at 10 locations along the gradient capturing distinct vegetation types and climate zones from lowland subtropical-forest to alpine-meadow. PLFA results showed that microbial communities were composed of 2.1–51.7% bacteria and 2.0–23.2% fungi across the elevation gradient. Microbial biomass was higher and the ratio of soil fungi to bacteria (F/B) was lower in forest soils compared to meadow soils. δ13C varied between −33‰ to −17‰ with C3 plant carbon sources dominant across the gradient. Soil organic carbon (SOC) turnover did not vary among three soils we measured from three forest types (i.e., evergreen broadleaved subtropical, mixed temperate, coniferous alpine) and dissolved organic carbon (DOC) turnover decreased with soil elevation. Forest soil microbial PLFA 14C and δ13C measurements showed that forest type and climate were related to different microbial C use. The 14C values of microbial PLFAs i15, a15, 16:1, br17 decreased with elevation while those of C16:0, cyC17, and cyC19 did not show much difference among three forest ecosystems. Bacteria and bacillus represented by C16:1 and brC17 showed considerable microbial C metabolism flexibility and tended to use ancient carbon at higher altitudes. Anaerobes represented by cyC17 and cyC19 showed stronger C metabolism selectivity. Our findings reveal specific C source differences between and within soil microbial groups along elevation gradients.
The aim of this study was to explore the frequency and distribution of gene mutations that are related to isoniazid (INH) and rifampin (RIF)-resistance in the strains of the multidrug-resistant tuberculosis (MDR-TB) Mycobacterium tuberculosis (M.tb) in Beijing, China. In this retrospective study, the genotypes of 173 MDR-TB strains were analysed by spoligotyping. The katG, inhA genes and the promoter region of inhA, in which genetic mutations confer INH resistance; and the rpoB gene, in which genetic mutations confer RIF resistance, were sequenced. The percentage of resistance-associated nucleotide alterations among the strains of different genotypes was also analysed. In total, 90.8% (157/173) of the MDR strains belonged to the Beijing genotype. Population characteristics were not significantly different among the strains of different genotypes. In total, 50.3% (87/173) strains had mutations at codon S315T of katG; 16.8% (29/173) of strains had mutations in the inhA promoter region; of them, 5.5% (15/173) had point mutations at −15 base (C→T) of the inhA promoter region. In total, 86.7% (150/173) strains had mutations at rpoB gene; of them, 40% (69/173) strains had mutations at codon S531L of rpoB. The frequency of mutations was not significantly higher in Beijing genotypic MDR strains than in non-Beijing genotypes. Beijing genotypic MDR-TB strains were spreading in Beijing and present a major challenge to TB control in this region. A high prevalence of katG Ser315Thr, inhA promoter region (−15C→T) and rpoB (S531L) mutations was observed. Molecular diagnostics based on gene mutations was a useful method for rapid detection of MDR-TB in Beijing, China.