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1.
J Med Genet ; 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32051257

RESUMO

BACKGROUND: Asthenoteratospermia, one of the most common causes for male infertility, often presents with defective sperm heads and/or flagella. Multiple morphological abnormalities of the sperm flagella (MMAF) is one of the common clinical manifestations of asthenoteratospermia. Variants in several genes including DNAH1, CEP135, CATSPER2 and SUN5 are involved in the genetic pathogenesis of asthenoteratospermia. However, more than half of the asthenoteratospermia cases cannot be explained by the known pathogenic genes. METHODS AND RESULTS: Two asthenoteratospermia-affected men with severe MMAF (absent flagella in >90% spermatozoa) from consanguineous families were subjected to whole-exome sequencing. The first proband had a homozygous missense mutation c.188G>A (p.Arg63Gln) of DZIP1 and the second proband had a homozygous stop-gain mutation c.690T>G (p.Tyr230*). Both of the mutations were neither detected in the human population genome data (1000 Genomes Project, Exome Aggregation Consortium) nor in our own data of a cohort of 875 Han Chinese control populations. DZIP1 encodes a DAZ (a protein deleted in azoospermia) interacting protein, which was associated with centrosomes in mammalian cells. Immunofluorescence staining of the centriolar protein Centrin1 indicated that the spermatozoa of the proband presented with abnormal centrosomes, including no concentrated centriolar dot or more than two centriolar dots. HEK293T cells transfected with two DZIP1-mutated constructs showed reduced DZIP1 level or truncated DZIP1. The Dzip1-knockout mice, generated by the CRSIPR-Cas9, revealed consistent phenotypes of severe MMAF. CONCLUSION: Our study strongly suggests that homozygous DZIP1 mutations can induce asthenoteratospermia with severe MMAF. The deficiency of DZIP1 induces sperm centrioles dysfunction and causes the absence of flagella.

2.
Breast Cancer Res ; 22(1): 12, 2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992350

RESUMO

BACKGROUND: Breast cancer intrinsic molecular subtype (IMS) as classified by the expression-based PAM50 assay is considered a strong prognostic feature, even when controlled for by standard clinicopathological features such as age, grade, and nodal status, yet the molecular testing required to elucidate these subtypes is not routinely performed. Furthermore, when such bulk assays as RNA sequencing are performed, intratumoral heterogeneity that may affect prognosis and therapeutic decision-making can be missed. METHODS: As a more facile and readily available method for determining IMS in breast cancer, we developed a deep learning approach for approximating PAM50 intrinsic subtyping using only whole-slide images of H&E-stained breast biopsy tissue sections. This algorithm was trained on images from 443 tumors that had previously undergone PAM50 subtyping to classify small patches of the images into four major molecular subtypes-Basal-like, HER2-enriched, Luminal A, and Luminal B-as well as Basal vs. non-Basal. The algorithm was subsequently used for subtype classification of a held-out set of 222 tumors. RESULTS: This deep learning image-based classifier correctly subtyped the majority of samples in the held-out set of tumors. However, in many cases, significant heterogeneity was observed in assigned subtypes across patches from within a single whole-slide image. We performed further analysis of heterogeneity, focusing on contrasting Luminal A and Basal-like subtypes because classifications from our deep learning algorithm-similar to PAM50-are associated with significant differences in survival between these two subtypes. Patients with tumors classified as heterogeneous were found to have survival intermediate between Luminal A and Basal patients, as well as more varied levels of hormone receptor expression patterns. CONCLUSIONS: Here, we present a method for minimizing manual work required to identify cancer-rich patches among all multiscale patches in H&E-stained WSIs that can be generalized to any indication. These results suggest that advanced deep machine learning methods that use only routinely collected whole-slide images can approximate RNA-seq-based molecular tests such as PAM50 and, importantly, may increase detection of heterogeneous tumors that may require more detailed subtype analysis.

3.
Medicine (Baltimore) ; 99(2): e18717, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31914085

RESUMO

BACKGROUND: Cardiac masses are rare, but lead to high risk of stroke and death. Because of the different treatment methods, it is significant for clinicians to differentiate the nature of masses. Cardiac magnetic resonance (CMR) imaging has high intrinsic soft-tissue contrast and high spatial and temporal resolution and can provide evidence for differential diagnosis of cardiac masses. However, there is no evidence-based conclusion as to its accuracy. Therefore, the purpose of our study is to perform a systematic review on this issue and provide useful information for clinical diagnosis and treatment. METHODS: We will perform a systematic search in EMBASE, Cochrane Library, PubMed and Web of Science for diagnostic studies using CMR to detect cardiac masses from inception to October, 2019. Two authors will independently screen titles and abstracts for relevance, review full texts for inclusion and conduct detail data extraction. The methodological quality will be assessed using the QUADAS-2 tool. If pooling is possible, we will use bivariate model for diagnostic meta-analysis to estimate summary sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio of CMR, as well as different sequences of CMR. Estimates of sensitivity and specificity from each study will be plotted in summary receive operating curve space and forest plots will be constructed for visual examination of variation in test accuracy. If enough studies are available, we will conduct sensitivity analysis and subgroup analysis. RESULTS: The results of this systematic review and meta-analysis will be published in a peer-reviewed journal. CONCLUSION: To our knowledge, this will be the first systematic review on the accuracy of CMR in the differential diagnosis of cardiac masses. This study will provide evidence and data to form a comprehensive understanding of the clinical value of CMR for cardiac masses patients. ETHICS AND DISSEMINATION: Ethics approval and patient consent are not required, as this study is a systematic review. PROSPERO REGISTRATION NUMBER: CRD42019137800.


Assuntos
Trombose Coronária/diagnóstico , Neoplasias Cardíacas/diagnóstico , Imagem por Ressonância Magnética/métodos , Trombose Coronária/diagnóstico por imagem , Diagnóstico Diferencial , Neoplasias Cardíacas/diagnóstico por imagem , Humanos , Projetos de Pesquisa , Sensibilidade e Especificidade
5.
BMC Cancer ; 20(1): 45, 2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-31959150

RESUMO

BACKGROUD: Pancreatic cancer is a highly malignant tumor of the digestive system. This secretome of pancreatic cancer is key to its progression and metastasis. But different methods of protein extraction affect the final results. In other words, the real secretion of proteins in cancer cells has been changed. Based on mass spectrometry, we analyze the secretome from the serum-containing and serum-free medium, using different protein pretreatment methods. This study aims to identify dissociation factors in pancreatic cancer. METHODS: In this study, pancreatic cancer cells were cultured in serum-containing or serum-free medium, and the corresponding supernatants were extracted as samples. Subsequently, the above samples were separated by size exclusion chromatography (SEC), and peptide segments were identified by LC-MS/MS. The final results were identified via the hamster secreted protein database and a public database. RESULTS: Although the number of identified proteins in the serum-free medium group was high, the real secretion of proteins in pancreatic cancer cells was changed. There were six significant secreted proteins in the serum-containing medium group. Survival analysis via the TCGA database suggested that patients with higher expression levels of YWHAG showed a worse overall survival rate than those with lower YWHAG expression. CONCLUSIONS: Our study demonstrated the results in the serum-containing medium group were more similar to the real secretome of pancreatic cancer cells. YWHAG could be used as a prognostic indicator for pancreatic cancer.

6.
Chemosphere ; 243: 125322, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31734592

RESUMO

The porous α-Fe2O3 microspheres (MS-Fe2O3) were obtained through in-situ ion exchange-calcination method and then utilized to activate persulfate (PS) for Rhodamine B (Rh B) degradation. The influences of some important operational parameters were investigated for the MS-Fe2O3/PS system. Additionally, the physicochemical properties of the as-fabricated MS-Fe2O3 were revealed with the assistance of some analytical instruments (i.e., X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectra (XPS), Brunauer-Emmett-Teller (BET) and vibrating sample magnetometer (VSM)). The results showed that the physicochemical properties of MS-Fe2O3 played an important role in the activation of PS, which promoted MS-Fe2O3 to effectively induce PS to generate reactive oxidizing species, thus Rh B could be nearly 100% degraded within 30 min under near-neutral pH solution. Noticeably, the as-prepared MS-Fe2O3 revealed magnetism and could be separated conveniently through external magnetic, which was beneficial to reuse the catalyst. Finally, the reactive oxidizing species (SO4- and OH) participating in the oxidation process were illustrated by electron paramagnetic resonance (EPR) and radical quenching studies, and then a rational mechanism was proposed to better understand the catalytic oxidation degradation of organic pollutants.

7.
Mediators Inflamm ; 2019: 6248197, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31827377

RESUMO

During organ culture of intact vessels, endothelin receptors (ETRs) were upregulated in vascular smooth muscle cells (VSMCs) by various stimuli, but whether inflammation alters ETR expression in vivo remains unclear. We aimed to explore the effects of lipopolysaccharide (LPS) challenge on ETR expression in the VSMC in vivo. Male Sprague-Dawley rats received a single intraperitoneal injection of LPS (5 mg/kg body weight) or normal saline (NS) for 6 hrs. The function and expression of ETR type A (ETA) and type B (ETB) were evaluated in the mesenteric arteries without endothelium, by using myograph system, real-time quantitative PCR, Western blot, and immunohistochemical staining, respectively. Serum tumor necrosis factor-α (TNF-α) level was assessed by using enzyme-linked immunosorbent assay. The results showed that, compared to control (NS) group, LPS treatment potently enhanced the vasoconstriction mediated by ETA or ETB in rat mesenteric artery, with elevated maximum effects. ETA and ETB expressions in the VSMC were increased at both mRNA and protein levels after LPS treatment, paralleled with activation of the NF-κB pathway and augmented serum TNF-α level. Conclusively, in the rat model of immediate systemic inflammation induced by LPS, ETA and ETB expressions were increased in the mesenteric arterial VSMC, paralleled with enhanced receptor-mediated vasoconstriction and activation of the NF-κB pathway. Our data has for the first time demonstrated the upregulation of ETRs in VSMCs by LPS-induced immediate inflammation in vivo.

8.
Int J Nurs Stud ; 102: 103483, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31835122

RESUMO

BACKGROUND: Pressure injuries are potentially preventable but frequently occurring adverse events. Intensive care patients have major risk factors for pressure injury with a reported pressure injury prevalence of 12-33%. Multi-faceted interventions, also known as programs or care bundles, are recommended to prevent pressure injuries. AIM: This systematic review evaluated the effectiveness of pressure injury prevention programs in reducing pressure injury prevalence and incidence in the adult intensive care population. It also critically appraised the program components and strategies used to implement these programs. METHOD: We searched PubMed, EMBASE (embase.com), Ovid MEDLINE, EBSCOhost CINAHL, and Cochrane Library databases separately for papers published in English and Chinese from the year of 2000 to May 2018. After removing duplicates, two authors independently screened the title and abstracts, then full-text against the inclusion and exclusion criteria. Data was extracted by one author and checked by a second author. Quality appraisal was conducted by two authors by using the Quality Improvement Minimum Quality Criteria Set, and the Mixed Methods Appraisal Tool. Content analysis was used to categorise program components. Implementation strategies were grouped into six classifications: dissemination strategies, implementation process strategies, integration strategies, capacity building strategies, sustainability strategies, and scale up strategies. RESULTS: Twenty-one peer reviewed papers (12 quality improvement projects, and 9 research papers from 8 studies) were included. Pressure injury prevention programs with 2-11 components were commonly implemented. Common components of the programs included: clarification of staff roles, introducing new roles, repositioning, staff and patient education, support surfaces use, pressure injury risk assessment, skin assessment, nutrition needs assessment, documentation, multidisciplinary team involvement, and mobilisation. Implementation strategies commonly used were education, audit and feedback, and standardising documentation. Five of the eight research studies and one of the quality improvement projects reported significant decrease in pressure injury prevalence, and/or increase in compliance to pressure injury prevention protocols and strategies. Two quality improvement papers reported cost savings of $1 million and £2.6 million respectively after the implementation of the programs. CONCLUSION: Much of the work on multicomponent pressure injury prevention programs has been undertaken as quality improvement projects and before and after research studies with limited rigour. However, positive outcomes and strong theoretical rationales for the components in the programs suggest that they are beneficial. This calls for future high-quality research such as randomised controlled trials to test the effectiveness of multicomponent interventions and their implementation strategies. Tweetable abstract: Some multicomponent pressure injury prevention programs were found to be effective; however, higher level of research evidence is needed.

9.
Sci Rep ; 9(1): 19931, 2019 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-31882717

RESUMO

In the present work, the biomass derived carbon decorated with humic acid (HC), was synthesized through impregnation method for the adsorption of phenol from water environment. Humic acids contain more oxygen-containing functional groups and hydrogen bonds, which promotes the binding between HC and phenol molecules. The results indicated that the adsorption performance of HC to phenol was better than that of commercial activated carbon. Moreover, in addition to physical absorption, the chemical reaction between carboxylic groups on the carbon surface and hydroxyl in phenol also played an important role during the process. The adsorption behavior of HC was described by equilibrium and kinetics parameters. Pseudo-second order model can describe the adsorption process well. Langmuir model was more suitable for the equilibrium adsorption data fitting, indicating that the adsorption mechanism of phenol on carbon surface tends to be monolayer adsorption. Considering practical application, UV254, chemical oxygen demand (COD) and ammonia from raw wastewater were selected as target contaminants and the corresponding adsorption experiments were carried out. The results displayed that HC exhibited excellent adsorption performance, especially for UV254, indicating that as-prepared carbon material had potential application for the control of certain organic pollutants in actual wastewater.

10.
BMJ Open ; 9(12): e033084, 2019 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-31871259

RESUMO

OBJECTIVE: To evaluate the diagnostic accuracy of transthoracic echocardiography (TTE) in patients with pulmonary hypertension (PH). DESIGN: Systematic review and meta-analysis. DATA SOURCES AND ELIGIBILITY CRITERIA: Embase, Cochrane Library for clinical trials, PubMed and Web of Science were used to search studies from inception to 19 June, 2019. Studies using both TTE and right heart catheterisation (RHC) to diagnose PH were included. MAIN RESULTS: A total of 27 studies involving 4386 subjects were considered as eligible for analysis. TTE had a pooled sensitivity of 85%, a pooled specificity of 74%, a pooled positive likelihood ratio of 3.2, a pooled negative likelihood ratio of 0.20, a pooled diagnostic OR of 16 and finally an area under the summary receiver operating characteristic curve of 0.88. The subgroup with the shortest time interval between TTE and RHC had the best diagnostic effect, with sensitivity, specificity and area under the curve (AUC) of 88%, 90% and 0.94, respectively. TTE had lower sensitivity (81%), specificity (61%) and AUC (0.73) in the subgroup of patients with definite lung diseases. Subgroup analysis also showed that different thresholds of TTE resulted in a different diagnostic performance in the diagnosis of PH. CONCLUSION: TTE has a clinical value in diagnosing PH, although it cannot yet replace RHC considered as the gold standard. The accuracy of TTE may be improved by shortening the time interval between TTE and RHC and by developing an appropriate threshold. TTE may not be suitable to assess pulmonary arterial pressure in patients with pulmonary diseases. PROSPERO REGISTRATION NUMBER: PROSPERO CRD42019123289.

12.
Pathogens ; 8(4)2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31717568

RESUMO

Brown blotch disease (BBD) caused by Pseudomonas tolaasii is one of the most devastating diseases of Pleurotus spp. worldwide. Breeding for resistant strains is the most effective method for controlling BBD. To identify resistant germplasm for BBD management, 97 strains comprising 21 P. cf. floridanus, 20 P. ostreatus, and 56 P. pulmonarius were screened by two different methods; namely, inoculation of the pathogen on the mushroom pileus (IMP) and on the spawned substrate (IMSS) under controlled conditions. Out of the 97 strains screened, 22 P. pulmonarius, and four P. cf. floridanus were moderately resistant to BBD using the IMP method. Eleven P. pulmonarius, six P. cf. florida, and one P. ostreatus strains were highly resistant to BBD using the IMSS method. All of the 97 strains showed varying degrees of susceptibility using the IMP method, but eight strains were completely resistant using the IMSS method. Combining these two methods, five strains were highly resistant (four P. pulmonarius and one P. cf. floridanus) and 11 were moderately resistant (eight P. pulmonarius and three P. cf. floridanus). The resistance sources to P. tolaasii identified in P. pulmonarius and P. cf. floridanus could be used for further breeding of Pleurotus spp.

13.
AMB Express ; 9(1): 184, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31728657

RESUMO

The "replacing wood by grass" project can partially resolve the conflict between mushroom production and balancing the ecosystem, while promoting agricultural economic sustainability. Pleurotus pulmonarius is an economically important edible and medicinal mushroom, which is traditionally produced using a substrate consisting of sawdust and cottonseed hulls, supplemented with wheat bran. A simplex lattice design was applied to systemically optimize the cultivation of P. pulmonarius using agro-residues as the main substrate to replace sawdust and cottonseed hulls. The effects of differing amounts of wheat straw, corn straw, and soybean straw on the variables of yield, mycelial growth rate, stipe length, pileus length, pileus width, and time to harvest were demonstrated. Results indicated that a mix of wheat straw, corn straw, and soybean straw may have significantly positive effects on each of these variables. The high yield comprehensive formula was then optimized to include 40.4% wheat straw, 20.3% corn straw, 18.3% soybean straw, combined with 20.0% wheat bran, and 1.0% light CaCO3 (C/N = 42.50). The biological efficiency was 15.2% greater than that of the control. Most encouraging was the indication that the high yield comprehensive formula may shorten the time to reach the reproductive stage by 6 days, compared with the control. Based on the results of this study, agro-residues may be used as a suitable substitution for sawdust and cottonseed hulls as the main cultivation substrates of P. pulmonarius. These results provide a theoretical basis for the "replacing wood by grass" project on edible mushroom cultivation.

14.
Cancer Cell Int ; 19: 262, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632196

RESUMO

Background: Pancreatic cancer is a malignancy with a very poor prognosis. The emergence of liquid biopsy is expected to achieve accurate early diagnosis through detection of tumor-derived secreted proteins in the blood. Early diagnosis and treatment of pancreatic cancer could help to improve prognosis. Methods: The pretreatment approach of samples can have a major effect on downstream analysis. In this study, we used a pair of homologous pancreatic cancer cell supernatants with different capacities for invasion and metastasis to examine secreted proteins in the conditioned media without the removal of fetal bovine serum, namely through size exclusion chromatography combined with high-abundance protein affinity chromatography to enrich low-concentration protein, followed by mass spectrometry using triple dimethyl labeling. Identification of proteins was performed using an online public database and western blot. Results: Mass spectrometry data revealed 77 proteins with quantitative properties, of which 12 proteins had over a 1.5-fold difference (in the supernatant of the highly invasive pancreatic cancer cell line PC-1.0, the expression of 8 proteins were increased and the expression of 4 proteins were decreased). Bioinformatics analysis results showed that CCT8, CTSL, SAA1, IGF2 are secreted via the exosome pathway. According to the literature, with the exception of CCT8, the other three proteins can be detected in blood samples of pancreatic cancer patients, and they can be used as prognostic markers. Western blot results were used to validate consistency with MS results. Conclusion: This study found that CCT8 can be used as a liquid biopsy marker to assess the prognosis of pancreatic cancer patients.

15.
Front Microbiol ; 10: 2255, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632371

RESUMO

Species in the genus Auricularia play important roles for people's food and nutrition especially Auricularia cornea and A. heimuer. To understand their evolutionary history, genome structure, and population-level genetic variation, we performed a high-quality genome sequencing of Auricularia cornea and the corresponding comparative genomic analysis. The genome size of A. cornea was similar to Auricularia subglabra, but 1.5 times larger than that of A. heimuer. Several factors were responsible for genome size variation including gene numbers, repetitive elements, and gene lengths. Phylogenomic analysis revealed that the estimated divergence time between A. heimuer and other Auricularia is ∼79.1 million years ago (Mya), while the divergence between A. cornea and A. subglabra occurred in ∼54.8 Mya. Population genomic analysis also provided insight into the demographic history of A. cornea and A. heimuer, indicating that their populations fluctuated over time with global climate change during Marine Isotope Stage 5-2. Moreover, despite the highly similar external morphologies of A. cornea and A. heimuer, their genomic properties were remarkably different. The A. cornea genome only shared 14% homologous syntenic blocks with A. heimuer and possessed more genes encoding carbohydrate-active enzymes and secondary metabolite biosynthesis proteins. The cross-taxa transferability rates of simple sequence repeat (SSR) and insertion or deletion (InDel) markers within the genus Auricularia were also lower than that previously observed for species within the same genus. Taken together, these results indicate a high level of genetic differentiation between these two Auricularia species. Consequently, our study provides new insights into the genomic evolution and genetic differentiation of Auricularia species that will facilitate future genetic breeding.

16.
Pathogens ; 8(4)2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31597275

RESUMO

Wet bubble disease, caused by Mycogone perniciosa, is a major threat to Agaricus bisporus production in China. In order to understand the variability of in genetic, pathogenicity, morphology, and symptom production of the fungus, 18 isolates of the pathogen were collected from diseased A. bisporus in different provinces in China. The isolates were characterized by a combination of morphological, cultural, and molecular pathogenicity testing on different strains of A. bisporus and amplified fragment length polymorphism (AFLP) analysis. The 18 isolates were identified by Koch's postulate and confirmed different pathogenic variability among them. The yellow to brown isolates were more virulent than the white isolates. AFLP markers clustered the isolates into two distinct groups based on their colony color, with a high level of polymorphism of Jaccard similarities ranges from 0.39% to 0.64%. However, there was no evidence of an association between the genetic diversity and the geographical origin of the isolates. Through knowledge of the genetic diversity, phenotypic virulence of M. perniciosa is a key factor for successful breeding of resistant strains of A. bisporus and developing of an integrated disease management strategy to manage wet bubble disease of A. bisporus.

17.
J Cell Mol Med ; 23(12): 8046-8057, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31631510

RESUMO

ß-thalassaemia is a prevalent hereditary haematological disease caused by mutations in the human haemoglobin ß (HBB) gene. Among them, the HBB IVS2-654 (C > T) mutation, which is in the intron, creates an aberrant splicing site. Bone marrow transplantation for curing ß-thalassaemia is limited due to the lack of matched donors. The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9), as a widely used tool for gene editing, is able to target specific sequence and create double-strand break (DSB), which can be combined with the single-stranded oligodeoxynucleotide (ssODN) to correct mutations. In this study, according to two different strategies, the HBB IVS2-654 mutation was seamlessly corrected in iPSCs by CRISPR/Cas9 system and ssODN. To reduce the occurrence of secondary cleavage, a more efficient strategy was adopted. The corrected iPSCs kept pluripotency and genome stability. Moreover, they could differentiate normally. Through CRISPR/Cas9 system and ssODN, our study provides improved strategies for gene correction of ß-Thalassaemia, and the expression of the HBB gene can be restored, which can be used for gene therapy in the future.

18.
PeerJ ; 7: e7631, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31534856

RESUMO

Atmospheric nitrogen (N) deposition and phosphorus (P) addition both can change soil bacterial and fungal community structure with a consequent impact on ecosystem functions. However, which factor plays an important role in regulating responses of bacterial and fungal community to N and P enrichments remains unclear. We conducted a manipulative experiment to simulate N and P inputs (10 g N · m-2 · yr-1 NH4NO3 or 10 g P · m-2 · yr-1 NaH2PO4) and compared their effects on soil bacterial and fungal species richness and community composition. The results showed that the addition of N significantly increased NH4 + and Al3+ by 99.6% and 57.4%, respectively, and consequently led to a decline in soil pH from 4.18 to 3.75 after a 5-year treatment. P addition increased Al3+ and available P by 27.0% and 10-fold, respectively, but had no effect on soil pH. N addition significantly decreased bacterial species richness and Shannon index and resulted in a substantial shift of bacterial community composition, whereas P addition did not. Neither N nor P addition changed fungal species richness, Shannon index, and fungal community composition. A structural equation model showed that the shift in bacterial community composition was related to an increase in soil acid cations. The principal component scores of soil nutrients showed a significantly positive relationship with fungal community composition. Our results suggest that N and P additions affect soil bacterial and fungal communities in different ways in subtropical forest. These findings highlight how the diversity of microbial communities of subtropical forest soil will depend on future scenarios of anthropogenic N deposition and P enrichment, with a particular sensitivity of bacterial community to N addition.

19.
J Phys Chem Lett ; 10(18): 5564-5570, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31475829

RESUMO

Janus transition metal dichalcogenides (TMDs) have recently emerged as a new class of two-dimensional materials with a vertical dipole moment. Here, using time-domain ab initio simulations, we show that electron-hole recombination can be substantially suppressed via different stacking orientations of bilayer MoSSe. Despite having a larger net dipole moment, a S-Se/S-Se oriented MoSSe bilayer has a shorter carrier lifetime due to strong nonadiabatic coupling and a small band gap. The electron-hole recombination is coupled to the interlayer out-of-plane motion. In contrast, the opposite vertical dipoles weaken interlayer interactions in symmetric oriented MoSSe bilayers. Consequently, initial and final states are localized within different layers, and this significantly suppresses carrier recombination, resulting in an order of magnitude longer excited carrier lifetime in Se-S/S-Se oriented MoSSe bilayers. Our simulations provide theoretical insights into the carrier dynamics and suggest a way to enhance the carrier lifetime in Janus TMDs for efficient energy harvesting.

20.
BMJ Open ; 9(8): e028705, 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31455705

RESUMO

OBJECTIVES: Although detecting breast cancer at an early stage through screening has been clearly shown to be an effective strategy, the screening participation rate in China remains low. This systematic review sought to synthesise the current evidence to identify factors associated with breast cancer screening participation among women in mainland China. DESIGN: This study was a systematic review. DATA SOURCES: Studies were collected from PubMed, PsycINFO, CINAHL, EMBASE and three major Chinese databases, specially China National Knowledge Infrastructure, Chongqing VIP and Wanfang Data. ELIGIBILITY CRITERIA: All included papers were original research studies with a longitudinal or cross-sectional study design that considered associated factors of breast cancer screening participation among women in mainland China. DATA EXTRACTION AND SYNTHESIS: Study selection, data extraction and quality assessment were conducted independently by two reviewers, involving a third to help reach a consensus when necessary. Primary outcomes of interest included factors associated with breast cancer screening participation. RESULTS: A total of 19 studies were included in this review. Based on these studies, geographical region, a personal history of breast disease, past screening behaviours for breast disease, physical examination and the availability of medical specialists/equipment for breast examination were consistently associated with participation in breast cancer screening, while residential area, ethnicity and attitude towards breast cancer screening appeared to be associated with participation in breast cancer screening. There were additionally some factors with even more limited evidence with which to ascertain their association with screening participation. CONCLUSIONS: There exists a wide range of factors that influence breast cancer screening participation in mainland China. These findings could help to inform future research and policy efforts.

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