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1.
Nature ; 614(7948): 456-462, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36792740

RESUMO

Stretchable hybrid devices have enabled high-fidelity implantable1-3 and on-skin4-6 monitoring of physiological signals. These devices typically contain soft modules that match the mechanical requirements in humans7,8 and soft robots9,10, rigid modules containing Si-based microelectronics11,12 and protective encapsulation modules13,14. To make such a system mechanically compliant, the interconnects between the modules need to tolerate stress concentration that may limit their stretching and ultimately cause debonding failure15-17. Here, we report a universal interface that can reliably connect soft, rigid and encapsulation modules together to form robust and highly stretchable devices in a plug-and-play manner. The interface, consisting of interpenetrating polymer and metal nanostructures, connects modules by simply pressing without using pastes. Its formation is depicted by a biphasic network growth model. Soft-soft modules joined by this interface achieved 600% and 180% mechanical and electrical stretchability, respectively. Soft and rigid modules can also be electrically connected using the above interface. Encapsulation on soft modules with this interface is strongly adhesive with an interfacial toughness of 0.24 N mm-1. As a proof of concept, we use this interface to assemble stretchable devices for in vivo neuromodulation and on-skin electromyography, with high signal quality and mechanical resistance. We expect such a plug-and-play interface to simplify and accelerate the development of on-skin and implantable stretchable devices.


Assuntos
Eletromiografia , Eletrônica Médica , Nanoestruturas , Maleabilidade , Polímeros , Próteses e Implantes , Dispositivos Eletrônicos Vestíveis , Humanos , Nanoestruturas/química , Polímeros/química , Pele , Monitorização Fisiológica , Eletrônica Médica/instrumentação , Eletrônica Médica/métodos , Eletromiografia/instrumentação
2.
Nature ; 624(7991): 295-302, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38092907

RESUMO

Connecting different electronic devices is usually straightforward because they have paired, standardized interfaces, in which the shapes and sizes match each other perfectly. Tissue-electronics interfaces, however, cannot be standardized, because tissues are soft1-3 and have arbitrary shapes and sizes4-6. Shape-adaptive wrapping and covering around irregularly sized and shaped objects have been achieved using heat-shrink films because they can contract largely and rapidly when heated7. However, these materials are unsuitable for biological applications because they are usually much harder than tissues and contract at temperatures higher than 90 °C (refs. 8,9). Therefore, it is challenging to prepare stimuli-responsive films with large and rapid contractions for which the stimuli and mechanical properties are compatible with vulnerable tissues and electronic integration processes. Here, inspired by spider silk10-12, we designed water-responsive supercontractile polymer films composed of poly(ethylene oxide) and poly(ethylene glycol)-α-cyclodextrin inclusion complex, which are initially dry, flexible and stable under ambient conditions, contract by more than 50% of their original length within seconds (about 30% per second) after wetting and become soft (about 100 kPa) and stretchable (around 600%) hydrogel thin films thereafter. This supercontraction is attributed to the aligned microporous hierarchical structures of the films, which also facilitate electronic integration. We used this film to fabricate shape-adaptive electrode arrays that simplify the implantation procedure through supercontraction and conformally wrap around nerves, muscles and hearts of different sizes when wetted for in vivo nerve stimulation and electrophysiological signal recording. This study demonstrates that this water-responsive material can play an important part in shaping the next-generation tissue-electronics interfaces as well as broadening the biomedical application of shape-adaptive materials.


Assuntos
Eletrofisiologia , Polímeros , Água , Animais , alfa-Ciclodextrinas/química , Eletrodos , Eletrofisiologia/instrumentação , Eletrofisiologia/métodos , Eletrofisiologia/tendências , Coração , Músculos , Polietilenoglicóis/química , Polímeros/química , Seda/química , Aranhas , Água/química , Hidrogéis/química , Eletrônica/instrumentação , Eletrônica/métodos , Eletrônica/tendências
3.
BMC Musculoskelet Disord ; 24(1): 901, 2023 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-37980469

RESUMO

BACKGROUND: Congenital muscular torticollis (CMT) is a common musculoskeletal disease affecting infants and young children. If CMT is not treated correctly and timely, it can lead to limited head and neck movements, head and neck deviation, and abnormal posture. In order to improve patients' symptoms and alleviate the negative impact of the disease on their lives, we are committed to exploring the treatment of CMT. METHODS: The general clinical and ultrasonographic data of 2599 children with CMT who received standardized treatment at Shenzhen Children's Hospital from 2004 to 2020 were retrospectively reviewed. According to given treatment, children with CMT were divided into the physiotherapy group, physiotherapy combined with glucocorticoid treatment group, and surgical treatment group. We divided children with CMT into local mass, uniform thickening, and atrophy according to ultrasound features. General clinical information, treatment, and ultrasound examination data in each group were compared. Additionally, electronic medical records of 2344 patients admitted due to CMT in 17 tertiary children's hospitals of China's Futang Research Center of Pediatric Development (FRCPD) from 2015 to 2019 were retrospectively analyzed. Data on sex, age, year of admission and discharge, and treatment costs during hospitalization were extracted from the first medical record pages according to the ICD codes. The data were assessed for normality using the Kolmogorov-Smirnov test. Depending on the data distribution, they were analyzed using parametric tests, such as the t-test, or non-parametric tests. Qualitative data are expressed as percentages (%) and analyzed using the chi-square or Fisher's exact probability test, with α = 0.05 as the test level. P < 0.05 was considered to be indicative of a statistically significant difference. RESULTS: Three types of CMT were defined based on sternocleidomastoid muscle ultrasound examination characteristics: local mass, uniform thickening, and atrophy. Age at first diagnosis was 69.21 ± 108.41 days in local mass type group, 216.85 ± 324.09 days in uniform thickening group, and 417.88 ± 739.05 days in atrophy- type group; while age at first physiotherapy use was 94.06 ± 206.49 days, 255.00 ± 430.62 days, 540.92 ± 1059.29 respectively. The children included in local mass type group have shown a high success rate of conservative treatment, with a rate of 7.5% of children underwent surgery. Age at first diagnosis was 112.44 ± 224.12 days in the physiotherapy group, 115.87 ± 144.86 days in the physiotherapy combined with glucocorticoid treatment subgroup, whereas the age at first physiotherapy use was 137.38 ± 312.11 and 196.91 ± 344.26 days respectively. In the observation period (2015-2019) the mean age at surgery for CMT in 17 tertiary children's hospitals of the FRCPD was 50 months. Overall, 663 children with CMT were 1-2 years of age, accounting for the largest proportion (28.3%). Followed by 417 individuals (17.8%) were 7-14 years of age, indicating that there are still more children with CMT receiving surgical treatment later. CONCLUSIONS: Early diagnosis and treatment are essential to improve the conservative treatment success rate and achieve good prognosis in children with CMT. Our team's concept for treating CMT is as follows: after diagnosing the children, we will adopt the standardized protocol of treatment, with physiotherapy combined with the injection of glucocorticoid drugs and SCM release surgery, when needed. This program has a high conservative treatment success rate and may facilitate the achievement of better prognosis and reduced teratogenicity rate.


Assuntos
Glucocorticoides , Torcicolo , Pré-Escolar , Humanos , Lactente , Atrofia , Hospitais , Estudos Retrospectivos , Torcicolo/diagnóstico por imagem , Torcicolo/epidemiologia , Torcicolo/terapia , Masculino , Feminino
4.
BMC Musculoskelet Disord ; 24(1): 598, 2023 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-37479999

RESUMO

BACKGROUND: In this study, to provide a theoretical basis for understanding the clinical characteristics of epiphyseal fractures in children and improving their management, we explored and analyzed the proportions of different types of epiphyseal fractures in children and evaluated the causes of injury and epidemiological characteristics. METHODS: We retrospectively analyzed children younger than 18 years with fresh epiphyseal fractures who were admitted to our hospital from July 2015 to February 2020. Demographic information, injury mechanisms, fracture characteristics, fracture classification and surgical information were collected. RESULTS: A total of 1124 pediatric patients (1147 epiphyseal fractures), including 789 boys and 335 girls, were included in this study. Epiphyseal fractures were classified as Salter-Harris type II (1002 cases), type IV (105 cases), type III (25 cases), Salter-Harris type I (14 cases), and Salter-Harris type V (1 case). The number of fracture sites peaked in the adolescent group (440 cases). The most three common sites of epiphyseal fractures were the distal radius (460 cases) in which Salter-Harris type II fractures were the most common (454 cases) and Salter-Harris type I (3 cases), Salter-Harris type IV (2 cases), Salter-Harris type III was the least common (1 case). Followed by phalanges of fingers (233 cases) in which Salter-Harris type II fractures were the most common (224 cases) and Salter-Harris type IV (4 cases), Salter-Harris type I (3 cases), Salter-Harris type III fractures were the least common (2 cases). Distal humerus (146 cases) in which Salter-Harris type II fractures were the most common (95 cases), followed by Salter-Harris type IV (49 cases), Salter-Harris type I fractures were the least common (2 cases). The most three important causes of fractures were falls (720 patients), car accident injuries (68 patients), and basketball falls (43 patients). Among the 1124 children with epiphyseal fractures, 1058 were treated mainly by surgery and the ratio of open and closed reduction was 1:5.3. Eighty-eight patients showed an interval > 72 h between the injury and the hospital visit. Among these 88 patients, the most common fracture type was distal radial epiphyseal fracture (32 cases), and all fractures were of Salter-Harris type II. CONCLUSIONS: The epidemiological characteristics of epiphyseal fractures in children indicate the need to strengthen health and safety education and protective measures to prevent the occurrence of these fractures in children. In addition, emergency surgeons and orthopedic surgeons in general hospitals should strengthen their basic knowledge of diagnosing and treating epiphyseal injuries in children to reduce missed diagnoses, misdiagnoses or malpractice.


Assuntos
Fraturas Ósseas , Fraturas Fechadas , Fraturas do Punho , Adolescente , Masculino , Feminino , Humanos , Criança , Estudos Retrospectivos , Dedos
5.
BMC Med Educ ; 23(1): 541, 2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37525126

RESUMO

BACKGROUND: Digital health is important for sustainable health systems and universal health coverage. Since the outbreak of COVID-19, many countries, including China, have promoted the introduction of digital health in their medical services. Developing the next generation of physicians with digital health knowledge and skills is a prerequisite for maximizing the potential of digital health. OBJECTIVE: We aimed to understand the perception of digital health among Chinese medical students, the current implementation of digital health education in China, and the urgent need of medical students. METHODS: Our cross-sectional survey was conducted online and anonymously among current medical students in China. We used descriptive statistical analysis to examine participant demographic characteristics and the demand for digital health education. Additional analysis was conducted by grouping responses by current participation in a digital health course. RESULTS: A total of 2122 valid responses were received from 467 medical schools. Most medical students had positive expectations that digital health will change the future of medicine. Compared with wearable devices (85.53%), telemedicine (84.16%), and medical big data (86.38%), fewer respondents believed in the benefits of clinical decision support systems (CDSS) (63.81%). Most respondents said they urgently needed digital health knowledge and skills, and the teaching method of practical training and internship (78.02%) was more popular than the traditional lecture (10.54%). However, only 41.45% wanted to learn about the ethical and legal issues surrounding digital health. CONCLUSIONS: Our study shows that the current needs of Chinese medical students for digital health education remain unmet. A national initiative on digital health education, is necessary and attention should be paid to digital health equity and education globally, focusing on CDSS and artificial intelligence. Ethics knowledge must also be included in medical curriculum. Students as Partners (SAP) is a promising approach for designing digital health courses.


Assuntos
COVID-19 , Estudantes de Medicina , Humanos , Estudos Transversais , Inteligência Artificial , COVID-19/epidemiologia , Currículo , Educação em Saúde
6.
Sensors (Basel) ; 23(3)2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36772779

RESUMO

Clear underwater images can help researchers detect cold seeps, gas hydrates, and biological resources. However, the quality of these images suffers from nonuniform lighting, a limited range of visibility, and unwanted signals. CycleGAN has been broadly studied in regard to underwater image enhancement, but it is difficult to apply the model for the further detection of Haima cold seeps in the South China Sea because the model can be difficult to train if the dataset used is not appropriate. In this article, we devise a new method of building a dataset using MSRCR and choose the best images based on the widely used UIQM scheme to build the dataset. The experimental results show that a good CycleGAN could be trained with the dataset using the proposed method. The model has good potential for applications in detecting the Haima cold seeps and can be applied to other cold seeps, such as the cold seeps in the North Sea. We conclude that the method used for building the dataset can be applied to train CycleGAN when enhancing images from cold seeps.

7.
Int J Mol Sci ; 24(14)2023 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-37511629

RESUMO

Gastric cancer (GC) is the third leading cause of cancer-related death worldwide. Due to the lack of early symptoms, GC is often diagnosed at an advanced stage when treatment options are limited. There is an urgent need to identify biomarkers for early detection, prognosis evaluation, and targeted treatment of GC. Studies have shown that Src kinase-associated phosphoprotein 1 (SKAP1) promotes cell proliferation and invasion and is associated with poor prognosis in colorectal cancer, malignant fibrous histiocytoma, and breast cancer. However, the role and mechanism of SKAP1 in GC are unclear. Here, analyses of multiple databases and experiments revealed that SKAP1 expression was higher in GC than in adjacent normal tissues. The Cancer Genome Atlas data showed that high SKAP1 expression was associated with poor GC prognosis. SKAP1 expression was higher in GC than in normal gastric epithelial cells. SKAP1 silencing reduced the proliferation, migration and invasion of the GC cell lines MKN45 and HGC27. Rescue experiments suggest that SKAP1 may promote GC progression by activating JAK1/PI3K/AKT signaling and regulating GC cell proliferation, invasion, migration, and other functions. Bioinformatics analysis revealed that SKAP1 was associated with immune cell infiltration and checkpoint expression in GC. High SKAP1 expression was associated with poorer immunotherapy outcomes, suggesting its potential as a predictive biomarker of GC immunotherapy efficacy. In summary, SKAP1 is overexpressed in GC, where it promotes cell proliferation, invasion and migration and is associated with poor prognosis and poor immunotherapy outcomes. SKAP1 may represent a biomarker and therapeutic target in GC and regulates cellular functions through JAK1/PI3K/AKT signaling.


Assuntos
Neoplasias Gástricas , Humanos , Neoplasias Gástricas/genética , Neoplasias Gástricas/terapia , Neoplasias Gástricas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Movimento Celular/genética , Proliferação de Células/genética , Biomarcadores , Regulação Neoplásica da Expressão Gênica , Linhagem Celular Tumoral , Fosfoproteínas/metabolismo
8.
J Environ Manage ; 347: 119078, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37757683

RESUMO

Grazing causes changes in microbiome metabolic pathways affecting plant growth and soil physicochemical properties. However, how grazing intensity affects microbial processes is poorly understood. In semiarid steppe grassland in northern China, shotgun metagenome sequencing was used to investigate variations in soil carbon (C) and nitrogen (N) cycling-related genes after six years of the following grazing intensities: G0, control, no grazing; G1, 170 sheep days ha-1 year-1; G2, 340 sheep days ha-1 year-1; and G3, 510 sheep days ha-1 year-1. Taxa and functions of the soil microbiome associated with the C cycle decreased with increasing grazing intensity. Abundances of genes involved in C fixation and organic matter decomposition were altered in grazed sites, which could effects on vegetation decomposition and soil dissolved organic carbon (DOC) content. Compared with the control, the abundances of nitrification genes were higher in G1, but the abundances of N reduction and denitrification genes were lower, suggesting that light grazing promoted nitrification, inhibited denitrification, and increased soil NO3- content. Q-PCR further revealed that the copies of genes responsible for carbon fixation (cbbL) and denitrification (norB) decreased with increasing grazing intensity. The highest copy numbers of the nitrification genes AOA and AOB were in G1, whereas copy numbers of the denitrification gene nirK were the lowest. A multivariate regression tree indicated that changes in C fixation genes were linked to changes in soil DOC content, whereas soil NO3- content was linked with nitrification and denitrification under grazing. Thus, genes associated with C fixation and the N cycle affected how C fixation and N storage influenced soil physicochemical properties under grazing. The findings indicate that grazing intensity affected C and N metabolism. Proper grassland management regimes (e.g., G1) are beneficial to the balances between ecological protection of grasslands and plant production in the semiarid steppe.


Assuntos
Pradaria , Solo , Animais , Ovinos , Solo/química , Metagenoma , Carbono/análise , Nitrogênio/análise , Microbiologia do Solo
9.
Clin Immunol ; 245: 109167, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36272701

RESUMO

Long non-coding RNAs (LncRNAs), lacking protein-coding function, modulate immune function by regulating the expression of genes or the function of protein molecules. They participate in epigenetic regulation, interfere with downstream gene transcription acting as a molecular sponge to affect miRNA function, and can combine with proteins to form nucleic acid protein complexes that affect protein function or cell location to regulate genes and regulate immune function. LncRNAs are differentially expressed in immune cells. They affect the maturity, differentiation and activation of immune cells and regulate cytokine release and immune phenotype. They are closely related to immune tolerance and cell migration. Dendritic cells (DCs) are important immune cells with the most robust antigen-presenting function, and have irreplaceable roles in human innate immunity and adaptive immunity. Emerging evidence over the past few years has suggested that LncRNAs influence the differentiation and maturation of DCs and serve as a critical role in the cell phenotype and immune function of DCs. To further understand the role of LncRNAs in the occurrence and development of DC-related diseases, we elaborated the role of LncRNAs in DC immune function, including antigen presentation, T cell activation and proliferation, DC migration. Furthermore, we summarized the impact of pathological factors (tumors, inflammation, autoimmune disease, viral infection) and physiological factors (e.g., age) on the LncRNAs in DCs, and how the changed LncRNAs altered the function and behavior of DCs resulting from the intervention. We hope this review give us have a better understanding of multiple effects of LncRNA on cell function in DCs.


Assuntos
MicroRNAs , RNA Longo não Codificante , Humanos , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Células Dendríticas , Epigênese Genética , Diferenciação Celular , MicroRNAs/metabolismo
10.
Clin Immunol ; 237: 108962, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35227870

RESUMO

Immune checkpoint inhibitors (ICIs), including anti-programmed cell death-1/anti-programmed cell death ligand-1 (anti-PD-1/PD-L1) therapy, have elicited impressive clinical outcomes in several malignancies. This is regarded as a pivotal breakthrough in cancer treatment. However, a vast majority of colorectal cancer (CRC) cases are microsatellite stable (MSS) and respond poorly to anti-PD-1/PD-L1 immunotherapies. Since ICIs serve as rescuers for immune cell-mediated cancer cell elimination, the limited efficacy of anti-PD-1/PD-L1 treatments may be attributed to the privileged tumor microenvironment (TME), which is characterized by unavailable immunosurveillance. Thus, it is essential to modify the pre-existing disordered immune system prior to the application of an anti-PD-1/PD-L1 therapy. In this review, to overcome unsatisfactory immunotherapy in CRC patients with MSS, we discussed various combination therapies based on TME reconstruction for improving the susceptibility to anti-PD-1/PD-L1 treatment.


Assuntos
Antígeno B7-H1 , Neoplasias Colorretais , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Humanos , Fatores Imunológicos/uso terapêutico , Imunoterapia , Instabilidade de Microssatélites , Microambiente Tumoral
11.
BMC Public Health ; 22(1): 1090, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35650559

RESUMO

BACKGROUND: Workplace violence is internationally recognised as a major concern for the workforce, which entails serious consequences, and research shows that medical residents are more likely than other doctors to experience violence in the workplace. This study first examines the effectiveness of simulation-based medical education, and then simulation-based medical education combined with behavioural economics as interventions in medical residents' perception of, attitude toward, and self-efficacy in coping with violence in the workplace. METHODS: A quasi-experimental design was used, 190 participants were randomised into three study groups to respectively test the effect of simulation-based medical education only and simulation-based medical education plus behavioural economics interventions, compared with a control group. Data were obtained from structured questionnaires, including (1) a perception of aggression scale, a management of aggression and violence attitude scale, a general self-efficacy scale, and (2) socio-demographic characteristics. RESULTS: The results show that the scores attained by simulation-based medical education (SBME) and simulation-based medical education combined with behavioural economics (SBME + BE) interventions for perception, attitude, and self-efficacy were significantly higher than those in the control group (p < .01). The SBME + BE group recorded a greater improvement in perception, which could be ascribed to the behavioural economics effect. Furthermore, the higher perception of workplace violence is correlated with single residents and those with more work experience, prior experiences of violence in the workplace, and training related to workplace violence. A higher positive correlation of workplace violence was recorded by female and widowed residents,and a higher level of self-efficacy related to violence in the workplace correlated with male, widowed,and senior (third-year) residents. CONCLUSIONS: This study contributes important evidence regarding changes in the perception, attitude, and self-efficacy of subjects following both the SBME + BE and SBME interventions among medical residents in coping with workplace violence, the biggest perception change having been recorded after the SBME + BE intervention, which can be explained by the inclusion of behavioural economics.


Assuntos
Internato e Residência , Violência no Trabalho , Adaptação Psicológica , Economia Comportamental , Feminino , Humanos , Masculino , Local de Trabalho , Violência no Trabalho/prevenção & controle
12.
BMC Musculoskelet Disord ; 23(1): 892, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36183061

RESUMO

PURPOSE: To investigate the factors influencing and long-term effects of manual myotomy (MM) occurring during physiotherapy for congenital muscular torticollis (CMT). METHODS: We retrospectively collected the clinical data of children with CMT receiving physiotherapy between 2008 and 2018. The children were divided into manual myotomy (MM) and non-manual myotomy (NMM) groups according to whether MM occurred during treatment. We assessed physiotherapy outcomes in children with CMT using craniofacial asymmetry parameters and the Cheng-Tang rating score. By measuring the ear-eye distance, ear-nose distance, eye-mouth distance, ear-mouth distance, half-head circumference, and half-head top at two sides to evaluate craniofacial asymmetry. Based on the Cheng-Tang assessment criteria, we recorded the range of rotation, range of lateral flexion, the status of the contracted muscle, the hardness of the mass, the extent of head tilting during activities and sleeping, the status of daily activities, face size, type of head shape, cranial changes, and subjective head tilting to assess the effectiveness of treatment. Clinical data and outcome indicators (craniofacial asymmetry parameters and Cheng-Tang rating score) were compared. RESULTS: The MM group had a significantly higher total Cheng-Tang rating score than the NMM group (P < 0.05). Age at initial physiotherapy session was the risk factor for MM during physiotherapy. CONCLUSION: Children with CMT developing MM during physiotherapy generally have a good outcome, although we do not recommend MM as a goal of treatment. Physiotherapists should understand this phenomenon, assess relevant factors to predict risk, and carefully observe treatment to prevent possible complications.


Assuntos
Fibroma , Miotomia , Torcicolo , Criança , Humanos , Lactente , Músculos do Pescoço , Modalidades de Fisioterapia , Estudos Retrospectivos , Torcicolo/complicações , Torcicolo/congênito , Torcicolo/cirurgia , Resultado do Tratamento
13.
J Environ Manage ; 321: 115919, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36001914

RESUMO

Plant and soil microbial community composition play a central role in maintaining ecosystem functioning. Most studies have focused on soil microbes in the bulk soil, the rhizosphere and inside plant roots, however, less is known about the soil community that exists within soil aggregates, and how these soil communities influence plant biomass production. Here, using field-conditioned soil collected from experimental ungrazed and grazed grasslands in Inner Mongolia, China, we examined the composition of microbiomes inside soil aggregates of various size classes, and determined their roles in plant-soil feedbacks (PSFs), diversity-productivity relationships, and diversity-dependent overyielding. We found that grazing induced significantly positive PSF effects, which appeared to be mediated by mycorrhizal fungi, particularly under plant monocultures. Despite this, non-additive effects of microbiomes within different soil aggregates enhanced the strength of PSF under ungrazed grassland, but decreased PSF strength under intensively grazed grassland. Plant mixture-related increases in PSF effects markedly enhanced diversity-dependent overyielding, primarily due to complementary effects. Selection effects played far less of a role. Our work suggests that PSF contributes to diversity-dependent overyielding in grasslands via non-additive effects of microbiomes within different soil aggregates. The implication of our work is that assessing the effectiveness of sustainable grassland restoration and management on soil properties requires inspection of soil aggregate size-specific microbiomes, as these are relevant determinants of the feedback interactions between soil and plant performance.


Assuntos
Microbiota , Solo , Biomassa , Ecossistema , Pradaria , Plantas , Microbiologia do Solo
14.
J Org Chem ; 86(1): 762-769, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33395741

RESUMO

We report a solvent-directed and regioselective carbon-carbon bond cleavage of aryl ketones by azido-1,3,5-triazines (ATs), which is typically completed within 10 min in DMSO at room temperature, without using transition metal catalysts. The cleavage is driven by the steric hindrance in the adducts of aryl ketones and ATs, which is substantiated by DFT calculation. Our recent results showed that ATs present high reactivity in solution and high stability in solid state. This "stability-reactivity paradox" has been explained in light of the molecular and crystal structures of ATs.

15.
Environ Sci Technol ; 55(11): 7256-7265, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34013726

RESUMO

Desert steppe, a unique ecotone between steppe and desert in Eurasia, is considered highly vulnerable to global change. However, the long-term impact of warming and nitrogen deposition on plant biomass production and ecosystem carbon exchange in a desert steppe remains unknown. A 12-year field experiment was conducted in a Stipa breviflora desert steppe in northern China. A split-design was used, with warming simulated by infrared radiators as the primary factor and N addition as the secondary factor. Our long-term experiment shows that warming did not change net ecosystem exchange (NEE) or total aboveground biomass (TAB) due to contrasting effects on C4 (23.4% increase) and C3 (11.4% decrease) plant biomass. However, nitrogen addition increased TAB by 9.3% and NEE by 26.0% by increasing soil available N content. Thus, the studied desert steppe did not switch from a carbon sink to a carbon source in response to global change and positively responded to nitrogen deposition. Our study indicates that the desert steppe may be resilient to long-term warming by regulating plant species with contrasting photosynthetic types and that nitrogen deposition could increase plant growth and carbon sequestration, providing negative feedback on climate change.


Assuntos
Ecossistema , Nitrogênio , Carbono , China , Nitrogênio/análise , Solo
16.
BMC Public Health ; 21(1): 1977, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34727917

RESUMO

BACKGROUND: With increasing urbanization in developing countries, sanitation workers are frequently involved in road traffic collisions. Our purpose was to study specific collisions involving sanitation workers and provide decision-making suggestions and reference measures for the sanitation industry and urban managers to reduce the occurrence of collisions. METHODS: We obtained online news data about sanitation worker road traffic collisions in China between 2013 and 2017 and analyzed occurrence time and location, victim characteristics, and causes of collisions. RESULTS: In China, between 2013 and 2017, 511 road traffic collisions were reported, with the fewest in February and July. Most occurred around 5:00 a.m. in Eastern regions and in urban areas. Victims were mainly over 50 years old, with more females than males. Collisions usually resulted in death at the scene. The ambiguity of laws, the exploitation of workers through industry outsourcing, and the difficulty of processing claims may be the main factors preventing victims from obtaining legal compensation. CONCLUSIONS: The most common cause of collisions was drivers' speeding, but workers also regularly risk death by crossing the road in pursuit of their duties. The absence of legal controls for environmental protection, the excessive pursuit of efficiency in urban governance, and the lack of basic education of sanitation workers are underlying causes of collisions. Raising awareness about sanitation worker road traffic collisions will help protect the work safety rights of this vulnerable group.


Assuntos
Acidentes de Trânsito , Saneamento , China/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
17.
BMC Public Health ; 20(1): 1164, 2020 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-32711503

RESUMO

BACKGROUND: The Coronavirus Disease 2019 (COVID-19) that first occurred in Wuhan, China, is currently spreading throughout China. The majority of infected patients either traveled to Wuhan or came into contact with an infected person from Wuhan. Investigating members of the public with a travel history to Wuhan became the primary focus of the Chinese government's epidemic prevention and control measures, but several instances of withheld histories were uncovered as localized clusters of infections broke out. This study investigated the public's willingness and beliefs associated with reporting travel history to high-risk epidemic regions, to provide effective suggestions and measures for encouraging travel reporting. METHODS: A cross-sectional study was conducted online between February 12 and 19, 2020. Descriptive analysis, chi-squared test, and Fisher's exact test were used to identify socio-demographic factors and beliefs associated with reporting, as well as their impact on the willingness to report on travel history to high-risk epidemic regions. RESULTS: Of the 1344 respondents, 91 (6.77%) expressed an inclination to deliberately withhold travel history. Those who understood the benefits of reporting and the legal consequences for deliberately withholding information, showed greater willingness to report their history (P < 0.05); conversely, those who believed reporting would stigmatize them and feared being quarantined after reporting showed less willingness to report (P < 0.05). CONCLUSIONS: As any incident of withheld history can have unpredictable outcomes, the proportion of people who deliberately withhold information deserves attention. Appropriate public risk communication and public advocacy strategies should be implemented to strengthen the understanding that reporting on travel history facilitates infection screening and prompt treatment, and to decrease the fear of potentially becoming quarantined after reporting. Additionally, social support and policies should be established, and measures should be taken to alleviate stigmatization and discrimination against potential patients and reporters of travel history. Reinforcing the legal accountability of withholding travel history and strengthening systematic community monitoring are the measures that China is currently taking to encourage reporting on travel history to high-risk epidemic regions. These non-pharmaceutical interventions are relevant for countries that are currently facing the spread of the epidemic and those at risk of its potential spread.


Assuntos
Infecções por Coronavirus/epidemiologia , Epidemias , Conhecimentos, Atitudes e Prática em Saúde , Pneumonia Viral/epidemiologia , Viagem/estatística & dados numéricos , Adulto , COVID-19 , China/epidemiologia , Infecções por Coronavirus/prevenção & controle , Estudos Transversais , Feminino , Governo , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Quarentena/psicologia , Medição de Risco , Adulto Jovem
18.
J Org Chem ; 83(18): 10916-10921, 2018 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-30122034

RESUMO

We report a crystalline compound 2-azido-4,6-dimethoxy-1,3,5-triazine (ADT) as an intrinsically safe, highly efficient, and shelf-stable diazo-transfer reagent. Because the decomposition of ADT is an endothermal process (Δ H = 30.3 kJ mol-1), ADT is intrinsically nonexplosive, as proved by thermal, friction, and impact tests. The diazo-transfer reaction based on ADT gives diazo compounds in excellent yields within several minutes at room temperature. ADT is very stable upon >1 year storage under air at room temperature.

20.
Ecology ; 98(6): 1631-1639, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28369715

RESUMO

Habitat destruction, characterized by patch loss and fragmentation, is a major driving force of species extinction, and understanding its mechanisms has become a central issue in biodiversity conservation. Numerous studies have explored the effect of patch loss on food web dynamics, but ignored the critical role of patch fragmentation. Here we develop an extended patch-dynamic model for a tri-trophic omnivory system with trophic-dependent dispersal in fragmented landscapes. We found that species display different vulnerabilities to both patch loss and fragmentation, depending on their dispersal range and trophic position. The resulting trophic structure varies depending on the degree of habitat loss and fragmentation, due to a tradeoff between bottom-up control on omnivores (dominated by patch loss) and dispersal limitation on intermediate consumers (dominated by patch fragmentation). Overall, we find that omnivory increases system robustness to habitat destruction relative to a simple food chain.


Assuntos
Biodiversidade , Ecossistema , Extinção Biológica , Cadeia Alimentar
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