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Although biodiversity and ecosystem functions are strongly shaped by contemporary environments, such as climate and local biotic and abiotic attributes, relatively little is known about how they depend on long-term geological processes. Here, along a 3000-m elevational gradient with tectonic faults on the Tibetan Plateau (that is, Galongla Mountain in Medog County, China), we study the joint effects of geological and contemporary environments on biological communities, such as the diversity and community composition of plants and soil bacteria, and ecosystem functions. We find that these biological communities and ecosystem functions generally show consistent elevational breakpoints at 2000–2800 m, which coincide with Indus-Yalu suture zone fault and are similar to the elevational breakpoints of soil bacteria on another mountain range 1000 km away. Mean annual temperature, soil pH and moisture are the primary contemporary determinants of biodiversity and ecosystem functions, which support previous findings. However, compared with the models excluding geological processes, inclusion of geological effects, such as parent rock and weathering, increases 67.9 and 35.9% of the explained variations in plant and bacterial communities, respectively. Such inclusion increases 27.6% of the explained variations in ecosystem functions. The geological processes thus provide additional links to ecosystem properties, which are prominent but show divergent effects on biodiversity and ecosystem functions: parent rock and weathering exert considerable direct effects on biodiversity, whereas indirectly influence ecosystem functions via interactions with biodiversity and contemporary environments. Thus, the integration of geological processes with environmental gradients could enhance our understanding of biodiversity and, ultimately, ecosystem functioning across different climatic zones.

Abstract Aim Community variation (i.e. beta diversity) along geographical gradients is of substantial interest in ecology and biodiversity reserves in the face of global changes. However, the generality in beta diversity patterns and underlying processes remains less studied across trophic levels and geographical regions. We documented beta diversity patterns and underlying ecological processes of stream bacteria, diatoms and macroinvertebrates along six elevational gradients. Locations Asia and Europe. Methods We examined stream communities using molecular and morphological methods. We characterised community uniqueness with local contributions to beta diversity (LCBD), and investigated the drivers of its geographic patterns using Mid‐Domain Effect (MDE), coenocline simulation, Raup‐Crick null model approach, and through comparisons to environmental factors. MDE is a stochastic model by considering species elevational range, while coenocline simulation is a deterministic model by considering species niche optima and tolerance. The null model provides possible underlying mechanisms of community assembly with the degree to which deterministic processes create communities deviating from those of null expectations. Results Across all taxa, we revealed a general U‐shaped LCBD‐elevation relationship, suggesting higher uniqueness of community composition at both elevational ends. This pattern was confirmed and could be explained by both stochastic and deterministic models, that is, MDE and coenocline simulation, respectively, and was supported by the dominance of species replacement. Temperature was the main environmental factor underlying elevational patterns in LCBD. The generalists with broad niche breadths were key in maintaining community uniqueness, and the higher relative importance of deterministic processes resulted in stronger U‐shaped patterns regardless of taxonomic group. Conclusions Our synthesis across both mountains and taxonomic groups clearly shows that there are consistent elevational patterns in LCBD among taxonomic groups, and that these patterns are explained by similar ecological mechanisms, producing a more complete picture for understanding and bridging the spatial variation in biodiversity under changing climate.

Complex microbial ecosystems harbor extensive intra-species diversity, but the fitness consequences of this genetic variation are poorly understood in community settings. Here we address this question by competing gut communities derived from different human donors, revealing the emergent fitness differences between conspecific strains as they competed within larger communities. Most pairs of strains experienced strong and context-dependent selection, even when their parent communities were originally selected in the same nutrient environment. However, these fitness differences typically attenuated over time due to biotic interactions within the community, leading to extended coexistence within many species, and competitive exclusion in others. These results support the view that conspecific strains can fulfill distinct ecological roles when competing within a diverse community, even when their genomic diversity exhibits the hallmarks of a single biological species.

Background Percutaneous transhepatic gallbladder drainage (PTGBD) is an alternative treatment for acute cholecystitis (AC). We aimed to understand the natural course of AC in patients treated with PTGBD but without later definitive treatments, such as laparoscopic cholecystectomy. Methods This was a retrospective study of the period from June 2010 to December 2016, during which time 2371 patients were diagnosed with AC and 625 received PTGBD treatment. Among the 625 patients, 237 received no definitive treatment. A biliary event after the initial AC episode was the outcome of interest. In addition, the competing risk of death unrelated to biliary causes was present in the cohort. Therefore, a competing risk model was applied for analysis. Results The cumulative incidence of biliary events was 29.8% with a median of 4.27 months, while the competing event, i.e., death unrelated to a biliary event, was noted in 14.9% of patients with a median 23.54 months. The risk factors of biliary events were prolonged PTGBD indwelling and an abnormal PTGBD cholangiogram. The risk factors of death unrelated to a biliary event included a high Charlson comorbidity index and the initial AC severity. Conclusions Definitive cholecystectomy is still recommended for patients undergoing PTGBD treatment due to the high incidence of later biliary events. A thorough preoperative evaluation is necessary for those patients before elective cholecystectomy because of the inferior life expectancy and physical status.

Abstract Aims Patients with type 2 diabetes (T2D) who undergo percutaneous coronary intervention (PCI) are at higher risk of adverse cardiovascular and renal events than non-diabetic patients. However, limited evidence is available regarding the cardiovascular, renal, and limb outcomes of patients with T2D after PCI and who were treated with sodium–glucose cotransporter-2 inhibitors (SGLT2i). We compare the specified outcomes in patients with T2D after PCI who were treated with SGLT2i vs. dipeptidyl peptidase-4 inhibitors (DPP4i). Methods and results In this nationwide retrospective cohort study, we identified 4248 and 37 037 consecutive patients with T2D who underwent PCI with SGLT2i and DPP4i, respectively, for 1 May 2016–31 December 2019. We used propensity score matching (PSM) to balance the covariates between study groups. After PSM, SGLT2i, and DPP4i were associated with comparable risks of ischaemic stroke, acute myocardial infarction, and lower limb amputation. However, SGLT2i was associated with significantly lower risks of heart failure hospitalization [HFH; 1.35% per year vs. 2.28% per year; hazard ratio (HR): 0.60; P = 0.0001], coronary revascularization (2.33% per year vs. 3.36% per year; HR: 0.69; P = 0.0003), composite renal outcomes (0.10% per year vs. 1.05% per year; HR: 0.17; P < 0.0001), and all-cause mortality (2.27% per year vs. 3.80% per year, HR: 0.60; P < 0.0001) than were DPP4i. Conclusion Our data indicated that SGLT2i, compared with DPP4i, were associated with lower risks of HFH, coronary revascularization, composite renal outcomes, and all-cause mortality for patients with T2D after PCI. Further randomized or prospective studies can investigate the effects of SGLT2i in patients with T2D after PCI.

PurposePercutaneous cholecystostomy (PC) is an important modality for acute cholecystitis and has been applied for other clinical scenarios as well. In the present study, we aimed to investigate an alternative use of PC for obstructive jaundice.MethodsFrom January 2012 to December 2018, eligible subjects were selected from patients undergoing PC in our institute. The characteristics, spectrum of underlying disease, indication for PC performance, details of the procedure, and treatment effect were all investigated.ResultsDuring the study period, 1364 patients underwent PC. Seventy patients fulfilled the defined inclusion criteria. While 47 patients were diagnosed with malignant biliary obstruction with or without cholangitis, 23 patients were diagnosed with nonmalignant biliary obstruction and acute cholangitis. There were 63 patients (90%) diagnosed with acute cholangitis. Pancreatic cancer (n = 24, 51%) and advanced malignancy (n = 28, 59%) were noted mostly in the group with malignant biliary obstruction. Treatment effects were proven by laboratory data, including the white blood cell count, C-reactive protein level, and hepatic function.ConclusionPC can temporize definitive therapies and serve as an alternative treatment for patients with nonmalignant conditions. For patients with advanced malignancy, PC can serve as a palliative procedure that has a high success rate and low complication rate and effectively relieves biliary obstruction.

Computed tomography (CT) plays an important role in diagnosing gastrointestinal perforation. This study explored the relationship between CT findings and the locations of perforated peptic ulcers (PPUs), which may help further surgical planning. During a 34-month period, 175 patients had CT scans. We categorized those 175 patients into 2 groups: patients with and without a PPU at a difficult ulcer site for a laparoscopic approach. Both clinical data and the CT images were reviewed and analyzed. Based on the univariate analysis results, we conducted multivariate analyses of 3 factors: age, American Society of Anesthesiologists classification of 3 or more, and positive lesser sac image findings. The positive lesser sac findings in CT were the only independent factor that was correlated to the PPU site. Positive lesser sac CT findings may help to predict PPUs in sites where a laparoscopic approach might be difficult. Our study re-evaluates the additional value of CT scanning in diagnosing PPU, and the results may assist with surgical planning in clinical practice. •This study determines the relationship between CT findings and PPU locations.•Some specific positive radiologic findings in CT scan may implicate the PPU location.•CT scan may be considered for patients who are candidates for laparoscopy procedure, regarding to anatomic detail and feasibility of laparoscopic approach.

Acute surgical abdomen is commonly encountered in the ED and CT is widely used as an informative diagnostic tool to evaluate potential surgical indications. However, the adverse effects of contrast material used in CTscanning have been documented. We sought to delineate the role of noncontrast CT in the evaluation of patients with acute surgical abdomen. Between August 2015 and December 2015, patients with nontraumatic surgical abdomen who underwent preoperative CT were enrolled in the current study. The patients for whom the CT results permitted surgical decision-making were the focus of this study. The disease entities included acute appendicitis, acute cholecystitis, hollow organ perforation, mechanical bowel obstruction, intra-abdominal abscess that could not be drained percutaneously, and ischemic bowel disease. The results of contrast-enhanced and noncontrast CT were compared and analyzed. The surgical conditions identifiable by noncontrast CT were recorded. In total, 227 patients were enrolled in the study. In 90.7 per cent of patients overall, the findings indicating the need for surgical treatment were visualized on both the noncontrast and contrast-enhanced images (acute appendicitis: 89.3%, acute cholecystitis: 89.7%, hollow organ perforation: 97.4%, bowel obstruction: 100%, intra-abdominal abscess: 100%, and ischemic bowel disease: 55.6%). Noncontrast CT provides benefit for critical decision-making. Body mass index may affect the accuracy of noncontrast imaging in the evaluation of patients with surgical abdomen. In some specific situations, contrast enhancement remains necessary.

Staphylococcus aureus δ-toxin is a member of the phenol-soluble modulin (PSM) peptide family. PSMs have multiple functions in staphylococcal pathogenesis; for example, they lyse red and white blood cells and trigger inflammatory responses. Compared to other PSMs, δ-toxin is usually more strongly expressed but has only moderate cytolytic capacities. The amino acid sequences of S. aureus PSMs are well conserved with two exceptions, one of which is the δ-toxin allelic variant G10S. This variant is a characteristic of the subspecies S. argenteus and S. aureus sequence types ST1 and ST59, the latter representing the most frequent cause of community-associated infections in Asia. δ-toxin G10S and strains expressing that variant from plasmids or the genome had significantly reduced cytolytic and pro-inflammatory capacities, including in a strain background with pronounced production of other PSMs. However, in murine infection models, isogenic strains expressing the two δ-toxin variants did not cause measurable differences in disease severity. Our findings indicate that the widespread G10S allelic variation of the δ-toxin locus has a significant impact on key pathogenesis mechanisms, but more potent members of the PSM peptide family may overshadow that impact in vivo .

A bstract In the application of on-shell recursion relation to string amplitudes, one challenge is the sum over infinite intermediate on-shell string states. In this note, we show how to sum these infinite states explicitly by including unphysical states to make complete Fock space.