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1.
Mol Cell ; 82(13): 2443-2457.e7, 2022 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-35613620

RESUMO

RAF protein kinases are effectors of the GTP-bound form of small guanosine triphosphatase RAS and function by phosphorylating MEK. We showed here that the expression of ARAF activated RAS in a kinase-independent manner. Binding of ARAF to RAS displaced the GTPase-activating protein NF1 and antagonized NF1-mediated inhibition of RAS. This reduced ERK-dependent inhibition of RAS and increased RAS-GTP. By this mechanism, ARAF regulated the duration and consequences of RTK-induced RAS activation and supported the RAS output of RTK-dependent tumor cells. In human lung cancers with EGFR mutation, amplification of ARAF was associated with acquired resistance to EGFR inhibitors, which was overcome by combining EGFR inhibitors with an inhibitor of the protein tyrosine phosphatase SHP2 to enhance inhibition of nucleotide exchange and RAS activation.


Assuntos
Neurofibromina 1 , Proteínas Proto-Oncogênicas A-raf , Proteínas Ativadoras de ras GTPase , Receptores ErbB/genética , Receptores ErbB/metabolismo , Guanosina Trifosfato/metabolismo , Humanos , Neurofibromina 1/metabolismo , Ligação Proteica , Proteínas Proto-Oncogênicas A-raf/metabolismo , Transdução de Sinais , Proteínas Ativadoras de ras GTPase/metabolismo
2.
Brief Bioinform ; 25(4)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38920346

RESUMO

Estimating transmission rates is a challenging yet essential aspect of comprehending and controlling the spread of infectious diseases. Various methods exist for estimating transmission rates, each with distinct assumptions, data needs, and constraints. This study introduces a novel phylogenetic approach called transRate, which integrates genetic information with traditional epidemiological approaches to estimate inter-population transmission rates. The phylogenetic method is statistically consistent as the sample size (i.e. the number of pathogen genomes) approaches infinity under the multi-population susceptible-infected-recovered model. Simulation analyses indicate that transRate can accurately estimate the transmission rate with a sample size of 200 ~ 400 pathogen genomes. Using transRate, we analyzed 40,028 high-quality sequences of SARS-CoV-2 in human hosts during the early pandemic. Our analysis uncovered significant transmission between populations even before widespread travel restrictions were implemented. The development of transRate provides valuable insights for scientists and public health officials to enhance their understanding of the pandemic's progression and aiding in preparedness for future viral outbreaks. As public databases for genomic sequences continue to expand, transRate is increasingly vital for tracking and mitigating the spread of infectious diseases.


Assuntos
COVID-19 , Filogenia , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/transmissão , COVID-19/epidemiologia , COVID-19/virologia , Pandemias , Doenças Transmissíveis/transmissão , Doenças Transmissíveis/epidemiologia , Genoma Viral
3.
Nature ; 579(7797): 67-72, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32094661

RESUMO

The Hall-Petch relationship, according to which the strength of a metal increases as the grain size decreases, has been reported to break down at a critical grain size of around 10 to 15 nanometres1,2. As the grain size decreases beyond this point, the dominant mechanism of deformation switches from a dislocation-mediated process to grain boundary sliding, leading to material softening. In one previous approach, stabilization of grain boundaries through relaxation and molybdenum segregation was used to prevent this softening effect in nickel-molybdenum alloys with grain sizes below 10 nanometres3. Here we track in situ the yield stress and deformation texturing of pure nickel samples of various average grain sizes using a diamond anvil cell coupled with radial X-ray diffraction. Our high-pressure experiments reveal continuous strengthening in samples with grain sizes from 200 nanometres down to 3 nanometres, with the strengthening enhanced (rather than reduced) at grain sizes smaller than 20 nanometres. We achieve a yield strength of approximately 4.2 gigapascals in our 3-nanometre-grain-size samples, ten times stronger than that of a commercial nickel material. A maximum flow stress of 10.2 gigapascals is obtained in nickel of grain size 3 nanometres for the pressure range studied here. We see similar patterns of compression strengthening in gold and palladium samples down to the smallest grain sizes. Simulations and transmission electron microscopy reveal that the high strength observed in nickel of grain size 3 nanometres is caused by the superposition of strengthening mechanisms: both partial and full dislocation hardening plus suppression of grain boundary plasticity. These insights contribute to the ongoing search for ultrastrong metals via materials engineering.

4.
Microb Ecol ; 87(1): 28, 2024 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-38182675

RESUMO

High mountain freshwater systems are particularly sensitive to the impacts of global warming and relevant environmental changes. Microorganisms contribute substantially to biogeochemical processes, yet their distribution patterns and driving mechanism in alpine streams remain understudied. Here, we examined the bacterial and fungal community compositions in stream biofilm along the elevational gradient of 745-1874 m on Mt. Kilimanjaro and explored their alpha and beta diversity patterns and the underlying environmental drivers. We found that the species richness and evenness monotonically increased towards higher elevations for bacteria, while were non-significant for fungi. However, both bacterial and fungal communities showed consistent elevational distance-decay relationships, i.e., the dissimilarity of assemblage composition increased with greater elevational differences. Bacterial alpha diversity patterns were mainly affected by chemical variables such as total nitrogen and phosphorus, while fungi were affected by physical variables such as riparian shading and stream width. Notably, climatic variables such as mean annual temperature strongly affected the elevational succession of bacterial and fungal community compositions. Our study is the first exploration of microbial biodiversity and their underlying driving mechanisms for stream ecosystems in tropical alpine regions. Our findings provide insights on the response patterns of tropical aquatic microbial community composition and diversity under climate change.


Assuntos
Microbiota , Rios , Tanzânia , Bactérias/genética , Biofilmes
5.
Environ Res ; 248: 118271, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38262515

RESUMO

Antibiotics and antibiotic resistance genes (ARGs), known as emerging contaminants, have raised widespread concern due to their potential environmental and human health risks. In this study, a conventional bioretention cell (C-BRC) and three modified bioretention cells with biochar (BC-BRC), microbial fuel cell coupled/biochar (EBC-BRC) and zero-valent iron/biochar (Fe/BC-BRC) were established and two antibiotics, namely sulfamethoxazole (SMX) and tetracycline (TC), were introduced into the systems in order to thoroughly investigate the co-stress associated with the long-term removal of pollutants, dynamics of microbial community, ARGs and functional genes in wastewater treatment. The results demonstrated that the SMX and TC co-stress significantly inhibited the removal of total nitrogen (TN) (C-BRC: 37.46%; BC-BRC: 41.64%; EBC-BRC: 55.60%) and total phosphorous (TP) (C-BRC: 53.11%; BC-BRC: 55.36%; EBC-BRC: 62.87%) in C-BRC, BC-BRC and EBC-BRC, respectively, while Fe/BC-BRC exhibited profoundly stable and high removal efficiencies (TN: 89.33%; TP: 98.36%). Remarkably, greater than 99% removals of SMX and TC were achieved in three modified BRCs compared with C-BRC (SMX: 30.86 %; TC: 59.29%). The decreasing absolute abundances of denitrifying bacteria and the low denitrification functional genes (nirK: 2.80 × 105-5.97 × 105 copies/g; nirS: 7.22 × 105-1.69 × 106 copies/g) were responsible for the lower TN removals in C-BRC, BC-BRC and EBC-BRC. The amendment of Fe/BC successfully detoxified SMX and TC to functional bacteria. Furthermore, the co-stress of antibiotics stimulated the propagation of ARGs (sulI, sulII, tetA and tetC) in substrates of all BRCs and only Fe/BC-BRC effectively reduced all the ARGs in effluent by an order of magnitude. The findings contribute to developing robust ecological wastewater treatment technologies to simultaneously remove nutrients and multiple antibiotics.


Assuntos
Antibacterianos , Carvão Vegetal , Microbiota , Humanos , Antibacterianos/farmacologia , Sulfametoxazol , Ferro , Genes Bacterianos , Tetraciclina/farmacologia , Resistência Microbiana a Medicamentos/genética , Bactérias
6.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 41(6): 749-752, 2024 Jun 10.
Artigo em Zh | MEDLINE | ID: mdl-38818563

RESUMO

OBJECTIVE: To analyze the clinical characteristics and genetic basis of a male patient with primary infertility caused by Acephalic spermatozoa syndrome. METHODS: A patient who had presented at the Henan Provincial People's Hospital on October 1, 2022 was selected as the study subject. Clinical data and results of laboratory exams and sperm electron microscopy were collected. The patient was subjected to whole exome sequencing (WES), and candidate variants were verified by Sanger sequencing and pathogenicity analysis. RESULTS: WES revealed that the patient has harbored compound heterozygous variants of the PMFBP1 gene, namely c.853del (p.Ala285Leufs*24) and c.1276A>T (p.Lys426X), which were both unreported previously. Sanger sequencing suggested that the c.853del (p.Ala285Leufs*24) variant has derived from his deceased mother, whilst the c.1276A>T (p.Lys426X) variant has derived from his father. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were classified as pathogenic (PVS1+PM2_Supporting+PP4). CONCLUSION: The compound heterozygous variants of the PMFBP1 gene probably underlay the Acephalic spermatozoa syndrome in this patient. The discovery of the novel variants has also enriched the mutational spectrum of Acephalic spermatozoa syndrome.


Assuntos
Espermatozoides , Humanos , Masculino , Adulto , Mutação , Sequenciamento do Exoma , Infertilidade Masculina/genética , Proteínas de Transporte/genética , Testes Genéticos , Teratozoospermia/genética , Proteínas dos Microfilamentos
7.
Anal Chem ; 95(7): 3883-3891, 2023 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-36745860

RESUMO

The loading, delivery, and release of Pt(IV) precursors in living organisms are important aspects of exploring the development of platinum drugs. In recent years, the biological application of the fluorescent sensors to platinum drugs has been insufficient to meet the study of Pt(IV) precursors. It is urgent to design and develop a biocompatible, multifunctional fluorescent sensor for the study of loading, transport, and release of Pt(IV) ions. Herein, we report a fluorescent molecule (E)-6-(diethylamino)-N'-(4-(diphenylamino) benzylidene)-2-oxo-2H-chromene-3 carbohydrazide (CHTPA). CHTPA has good sensitivity and selectivity to Pt(IV) when the water content is 5%, and significant increase of the fluorescence emission intensity of CHTPA is observed with Pt(IV) concentration. The sensing mechanism is attributed to photo-induced electron transfer, which is verified by X-ray absorption near edge spectroscopy spectra, UV-vis absorption spectroscopy, 1H NMR spectra, and Fourier transform infrared spectra. Furthermore, the CHTPA-Pt(IV) complex is able to release Pt(IV) in aqueous solution, and the green fluorescence of CHTPA based on the aggregation-induced emission effect can be observed. Inspired by these, the amphiphilic block copolymer poly(ethyloxide)-block-polystyrene (PEO-b-PS) is used to prepare the nonconjugated polymer dots (Pdots). The experimental results show that Pdots can effectively slow down the release speed of Pt(IV) in aqueous solution and it has a great monodispersity in aqueous solution. Meanwhile, Pdots show low cytotoxicity, and this is favorable for intracellular applications. The investigation of cellular imaging indicates that these Pdots can act as a carrier to deliver Pt(IV) into MCF-7 cells for visualized delivery and sustained release of platinum(IV) ions. Therefore, this study provides a new avenue to design and develop a biocompatible multifunctional fluorescent sensor for studying the loading, delivery, and release of Pt(IV) in cells.


Assuntos
Corantes Fluorescentes , Platina , Humanos , Platina/química , Preparações de Ação Retardada , Células HeLa , Corantes Fluorescentes/química , Íons
8.
Cell Mol Neurobiol ; 43(1): 69-78, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34988760

RESUMO

Cerebral ischemic stroke is one of the leading causes of morbidity and mortality worldwide, and rapidly increasing annually with no more effective therapeutic measures. Thus, the novel diagnostic and prognostic biomarkers are urgent to be identified for prevention and therapy of ischemic stroke. Recently, long noncoding RNAs (lncRNAs), a major family of noncoding RNAs with more than 200 nucleotides, have been considered as new targets for modulating pathological process of ischemic stroke. In this review, we summarized that the lncRNA-maternally expressed gene 3 (MEG3) played a critical role in promotion of neuronal cell death and inhibition of angiogenesis in response to hypoxia or ischemia condition, and further described the challenge of overcrossing blood-brain barrier (BBB) and determination of optimal carrier for delivering lncRNA' drugs into the specific brain regions. In brief, MEG3 will be a potential diagnostic biomarker and drug target in treatment and therapy of ischemic stroke in the future.


Assuntos
Isquemia Encefálica , AVC Isquêmico , RNA Longo não Codificante , Acidente Vascular Cerebral , Humanos , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , AVC Isquêmico/genética , Acidente Vascular Cerebral/metabolismo , Isquemia Encefálica/metabolismo , Isquemia
9.
Langmuir ; 39(2): 890-898, 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36603177

RESUMO

Exploring highly efficient microwave absorption (MA) materials with a facile preparation method is of great significance for tackling electromagnetic pollution and remains a challenge. Herein, ternary MoO2/Mo2C/Mo2N composites with porous structures are fabricated by a simple precursor pyrolysis process. The unique structure and multiple components, which could generate sufficient heterogeneous interfaces, are conducive to improve impedance matching, trigger polarization loss, and strengthen conduction loss. Profiting from the synergistic effect of multiple dissipation mechanisms, the composites exhibit exceedingly good MA performance. The minimum reflection loss value reaches -38.0 dB at 10.4 GHz when the thickness is 2.0 mm, and the maximum effective absorbing bandwidth is 4.11 GHz ranged from 12.41 to 16.52 GHz when the thickness is 1.5 mm. These strategies pave opportunities for rational design of Mo-related composites for high-efficiency electromagnetic-wave absorption performance.

10.
Scand J Gastroenterol ; 58(1): 38-44, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35850581

RESUMO

OBJECTIVES: Limited literature exists on the characteristics of early gastric signet ring cell carcinoma (GSRCC) within 20 mm. This study aimed to explore this type of cancer from several aspects, to provide guidance for early detection and intervention of GSRCC. METHODS: We retrospectively collected data from 24 patients diagnosed with early GSRCC ≤20 mm in Beijing Friendship Hospital from 2016 to 2021. According to tumor size, those lesions were divided into three groups: diminutive group (1-5 mm, n = 4), small group (6-10 mm, n = 12) and intermediate group (11-20 mm, n = 8). The clinicopathologic and endoscopic characteristics of GSRCC were compared among the three groups. RESULTS: Treatment strategies for lesions differed according to the size (p<.05). There were no significant differences among the three groups with regard to age, sex, Helicobacter pylori infection, tumor location and macroscopic type. Lesions were often flat type and more likely to present with discoloration, uneven color, ulceration and submucosal invasion with the increase of diameter. Almost all cases showed abnormal intervening part (IP) under magnifying endoscopy. CONCLUSIONS: The location of early signet ring cell carcinoma is not specific, and the diminutive lesions are often flat. Abnormal IP may be the early endoscopic feature of early GSRCC.


Assuntos
Carcinoma de Células em Anel de Sinete , Infecções por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Humanos , Estudos Retrospectivos , Detecção Precoce de Câncer , Carcinoma de Células em Anel de Sinete/diagnóstico , Carcinoma de Células em Anel de Sinete/patologia , Neoplasias Gástricas/patologia , Endoscopia Gastrointestinal
11.
Ann Pharmacother ; : 10600280231210275, 2023 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-37946374

RESUMO

BACKGROUND: Fluoroquinolones (FQs) are associated with increased risk of tendon injury but comparative risk versus other antibiotic options for the same indication has yet to be evaluated. OBJECTIVE: Describe the incidence (relative risk) of any tendon injury in patients receiving FQ compared with other (non-FQs) antibiotics for treatment of community-acquired pneumonia (CAP). METHODS: A retrospective propensity score weighted cohort study was performed to evaluate the association between FQ antibiotics and tendon injury risk at 2 time points (within 1 month and within 6 months of use) compared with non-FQ regimens for treatment of CAP. The evaluation was performed using the CCAE (MarketScan Commercial Claims and Encounters) and COB (Medicare Supplemental and Coordination of Benefits) databases from 2014 to 2020. Patients with ICD (International Classification of Diseases) 9/10 coding for outpatient pneumonia who were >18 years and without history of tendon injury were included. Patients with history of tendon injury, who received multiple antibiotic therapies for recurrent pneumonia, or who received both FQ and non-FQ regimens during the study period were excluded. Propensity score weighting was used to adjust for selection bias due to contributing risk factors, including demographics (age, sex), comorbidities (diabetes mellitus, chronic kidney disease), and concurrent medications (corticosteroids). RESULTS: At 1 month, the odds of tendon injury were estimated to be significantly higher (41.9%) in patients receiving FQs compared with those receiving a non-FQ-based regimen (odds ratio [OR] = 1.419, 95% confidence interval [CI] = [1.188-1.698]). The odds of tendon injury were also estimated to be higher (OR = 1.067, 95% CI = [0.975-1.173]) in the FQ population within 180 days, but this effect was not statistically significant. The most frequent sites of tendon injuries were rotator cuff, shoulder, and patellar tendon. CONCLUSIONS AND RELEVANCE: Prescribers should recognize the risk of tendon injury within 1 month of FQ use when considering treatment regimens for CAP and use alternative options with lower risk whenever possible.

12.
J Med Internet Res ; 25: e46092, 2023 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-37494107

RESUMO

BACKGROUND: Telephone-assisted cardiopulmonary resuscitation (T-CPR) has proven to be a crucial intervention in enhancing the ability of lay responders to perform cardiopulmonary resuscitation (CPR) during telehealth emergency services. While the majority of established T-CPR protocols primarily focus on guiding individual rescuers, there is a lack of emphasis on instructing and coordinating multiple lay responders to perform resuscitation collaboratively. OBJECTIVE: This study aimed to develop an innovative team-based tele-instruction tool to efficiently organize and instruct multiple lay responders on the CPR process and to evaluate the effectiveness and feasibility of the tool. METHODS: We used a mixed methods design in this study. We conducted a randomized controlled simulation trial to conduct the quantitative analysis. The intervention groups used the team-based tele-instruction tool for team resuscitation, while the control groups did not have access to the tool. Baseline resuscitation was performed during the initial phase (phase I test). Subsequently, all teams watched a team-based CPR education training video and finished a 3-person practice session with teaching followed by a posttraining test (phase II test). In the qualitative analysis, we randomly selected an individual from each team and 4 experts in emergency medical services to conduct semistructured interviews. The purpose of these interviews was to evaluate the effectiveness and feasibility of this tool. RESULTS: The team-based tele-instruction tool significantly improved the quality of chest compression in both phase I and phase II tests. The average compression rates were more appropriate in the intervention groups compared to the control groups (median 104.5, IQR 98.8-111.8 min-1 vs median 112, IQR 106-120.8 min-1; P=.04 in phase I and median 117.5, IQR 112.3-125 min-1 vs median 111, IQR 105.3-119 min-1; P=.03 in phase II). In the intervention group, there was a delay in the emergency response time compared to that in the control group (time to first chest compression: median 20, IQR 15-24.8 seconds vs median 25, IQR 20.5-40.3 seconds; P=.03; time to open the airway: median 48, IQR 36.3-62 seconds vs median 73.5, IQR 54.5-227.8 seconds; P=.01). However, this delay was partially mitigated after the phase II test. The qualitative results confirmed the compatibility and generalizability of the team-based tele-instruction tool, demonstrating its ability to effectively guide multiple lay responders through teamwork and effective communication with telecommunicators. CONCLUSIONS: The use of the team-based tele-instruction tool offers an effective solution to enhance the quality of chest compression among multiple lay responders. This tool facilitated the organization of resuscitation teams by dispatchers and enabled efficient cooperation. Further assessment of the widespread adoption and practical application of the team-based tele-instruction tools in real-life rescue scenarios within the telehealth emergency services system is warranted.


Assuntos
Reanimação Cardiopulmonar , Serviços Médicos de Emergência , Telemedicina , Humanos , Reanimação Cardiopulmonar/educação , Telefone
13.
Ecotoxicol Environ Saf ; 249: 114431, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36521269

RESUMO

The aquatic system is a major sink for engineered nanomaterials released into the environment. Here, we assessed the toxicity of graphene oxide (GO) using the freshwater planarian Dugesia japonica, an invertebrate model that has been widely used for studying the effects of toxins on tissue regeneration and neuronal development. GO not only impaired the growth of normal (homeostatic) worms, but also inhibited the regeneration processes of regenerating (amputated) worms, with LC10 values of 9.86 mg/L and 9.32 mg/L for the 48-h acute toxicity test, respectively. High concentration (200 mg/L) of GO killed all the worms after 3 (regenerating) or 4 (homeostasis) days of exposure. Whole-mount in situ hybridization (WISH) and immunofluorescence analyses suggest GO impaired stem cell proliferation and differentiation, and subsequently caused cell apoptosis and oxidative DNA damage during planarian regeneration. Mechanistic analysis suggests that GO disturbed the antioxidative system (enzymatic and non-enzymatic) and energy metabolism in the planarian at both molecular and genetic levels, thus causing reactive oxygen species (ROS) over accumulation and oxidative damage, including oxidative DNA damage, loss of mitochondrial membrane integrity, lack of energy supply for cell differentiation and proliferation leading to retardance of neuron regeneration. The intrinsic oxidative potential of GO contributes to the GO-induced toxicity in planarians. These data suggest that GO in aquatic systems can cause oxidative stress and neurotoxicity in planarians. Overall, regenerated tissues are more sensitive to GO toxicity than homeostatic ones, suggesting that careful handling and appropriate decisions are needed in the application of GO to achieve healing and tissue regeneration.


Assuntos
Planárias , Animais , Planárias/genética , Homeostase/fisiologia , Apoptose , Oxirredução , Água Doce
14.
BMC Surg ; 23(1): 352, 2023 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-37980470

RESUMO

OBJECTIVE: The aim of this study was to investigate the clinical efficacy of small plate assisted anatomical plate and traditional double plate in the treatment of Rüedi and Allgöwer II - III pilon fracture. METHODS AND MATERIALS: The data of 68 patients with pilon fracture admitted to Hospital from June 2017 to June 2020 were retrospectively analyzed. Study group and control group were divided according to different operation methods, with 34 cases in each group. There were 28 cases of Rüedi and Allgöwer II type and 40 cases of Rüedi and Allgöwer III type. Perioperative period data, Ankle joint function score, visual analog scale (VAS) scores and the incidence of incision complications were analyzed between these two groups. RESULTS: There were no significant differences in full load time, fracture healing time between these two groups (P > 0.05). The operation time, intraoperative blood loss, length of hospital stay, Ankle joint function score and postoperative incision complication rate in observation group were lower than those in control group (P < 0.05). CONCLUSION: Small plate assisted anatomic plate is comparable to traditional double plate in the treatment of pilon fracture in terms of complete loading time, fracture healing time, but the former can shorten the operation time, reduce intraoperative blood loss and effectively reduce the incidence of postoperative complications.


Assuntos
Fraturas do Tornozelo , Fraturas da Tíbia , Humanos , Estudos Retrospectivos , Perda Sanguínea Cirúrgica , Fixação Interna de Fraturas/métodos , Fraturas da Tíbia/cirurgia , Fraturas do Tornozelo/diagnóstico por imagem , Fraturas do Tornozelo/cirurgia , Resultado do Tratamento , Complicações Pós-Operatórias
15.
Angew Chem Int Ed Engl ; 62(10): e202216060, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36640110

RESUMO

Constructing the backbones of polymers with metal atoms is an attractive strategy to develop new functional polymeric materials, but it has yet to be studied due to synthetic challenges. Here, metal atoms are interconnected as the backbones of polymers to yield metal-backboned polymers (MBPs). Rational design of multidentate ligands synthesized via an efficient iterative approach leads to the successful construction of a series of nickel-backboned polymers (NBPs) with well-defined lengths and up to 21 nickel atoms, whose structures are systematically confirmed. These NBPs exhibit strong and length-depended absorption with narrow band gaps, offering promising applications in optoelectronic devices and semiconductors. We also demonstrate the high thermal stability and solution processsability of such nickel-backboned polymers. Our results represent a new opportunity to design and synthesize a variety of new metal-backboned polymers for promising applications in the future.

16.
Inorg Chem ; 60(3): 2087-2096, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33470793

RESUMO

Mixed-matrix membranes (MMMs) incorporating metal-organic framework crystalline fillers as heterogeneous catalysts for organic transformation reactions have attracted more attention in catalysis science. Herein, a new 3D cadmium metal-organic framework (H3O)·[Cd(dppa)] (1) was first synthesized using the rigid 4-(3,5-dicarboxylphenyl)picolinic acid (H3dppa) as an organic ligand under solvothermal conditions, exhibiting a novel 6,6-connected network and good tolerance to various solvents. After activation, 1 showed good catalytic reactivity and selectivity for the synthesis of benzimidazole derivatives, affording solvent-dependent catalytic activity. Then, using the microcrystals of 1 and poly(vinylidene fluoride) (PVDF) as raw materials, 1@PVDF MMMs were successfully prepared by polymer solution casting. Notably, the integration of MOF and PVDF endows the mixed-matrix membrane 1@PVDF with great advantages in terms of more dispersive Lewis acid catalytic sites and recyclability. As expected, 1@PVDF not only displays good catalytic activity comparable to that of activated 1 but also exhibits remarkable recyclability and continuous usability for the production of benzimidazole and α- or ß-amino acid derivatives. To the best of our knowledge, this is the first time that a Cd-based MOF and MMMs have been applied as a catalyst for the production of a ß-amino acid. The combination of catalytic MOF and PVDF provides a way to simplify the design of a flow reactor and reduce the costs of manufacturing.

17.
Environ Res ; 200: 111746, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34302829

RESUMO

Melatonin is produced by plants, algae, and animals. Worldwide studies show diverse positive effects of exogenous melatonin on plants, edible plant products, and algae, but the potential of melatonin to enhance food and feed systems through these positive effects remains largely unexplored. Through a meta-analysis of about 25,000 observations, we show for the first time that exogenous application of melatonin significantly increases crop productivity and yields, and enhances the nutritional and nutraceutical value of edible plant products and algae by regulating diverse biological functions. We demonstrate that melatonin can improve plants, edible plant products, and algae under various current climate change scenarios, environmental pollution factors, and other stresses by about 7% to nearly 30%, on average, depending on the stressor. We also analyze various technical/methodological factors influencing the desired outcomes and identify conditions that offer optimal enhancement. We show that the positive effect of melatonin on plants and edible plant products varies among species, genera, and families, and strongly depends on the concentration of melatonin and treatment duration. The effect of melatonin is slightly lower on the monocot clade Commelinids than on the eudicot clades Asterids and Rosids. We also show that its stimulatory effect on plants depends on cultivation system, with a larger effect obtained in hydroponic systems. However, it does not depend on application stage (seed or vegetative), application route (foliage, roots, or seed), and whether the cultivation system is ex vivo or in vivo. This is the first meta-analysis examining the effects of melatonin on plants, edible plant products, and algae, and offers a scientific and technical roadmap facilitating sustainable food and feed production through the application of exogenous melatonin.


Assuntos
Melatonina , Agricultura , Animais , Suplementos Nutricionais , Raízes de Plantas , Plantas
18.
Pol J Pathol ; 72(4): 324-330, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35308003

RESUMO

Immunotherapy can reverse tumor immune escape by suppressing immune checkpoints. Lymphocyte activation gene 3 (LAG3) is an important checkpoint and its role in colorectal cancer is not clear. In this study, we investigated LAG3 protein expression and its correlation with clinicopathologic parameters. The expression of LAG3 protein was assessed in 150 surgically resected colorectal cancer tissue samples by immunohistochemistry. The relationship between LAG3 expression and clinicopathological parameters, MSI status and survival was statistically analyzed. LAG3 protein was not expressed in colorectal cancer cells, and was expressed on the tumor-infiltrating lymphocytes (TILs) in 31 out of 150 (20.7%) colorectal cancer samples. Positive expression of LAG3 in TILs is associated with lymph node metastasis (p < 0.001), TNM stage (p = 0.024) and MSI-H (p = 0.035). No significant relationship was found between LAG3 expression and gender, age, tumor location, tumor invasion depth, and differentiation. LAG3 expression is associated with longer overall survival (p = 0.045). Our data show LAG3 expression on TILs in parts of CRC tissue. Positive expression of LAG3 was associated with advanced tumor stage, MSI-H and a poor prognosis. We conclude that LAG3 is an important checkpoint gene in CRC and may be a potential marker for prognosis of CRC.


Assuntos
Neoplasias Colorretais , Linfócitos do Interstício Tumoral , Neoplasias Colorretais/patologia , Humanos , Imuno-Histoquímica , Instabilidade de Microssatélites , Prognóstico
19.
BMC Plant Biol ; 19(1): 60, 2019 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-30727953

RESUMO

BACKGROUND: Tubby-like proteins (TLPs), characterized by a signature tubby domain, are widespread in plants and animals. To date, only plant TLPs involved in multifarious stress responses and male gametophyte development have been identified. However, studies on the molecular functions of plant TLPs are largely unknown. RESULTS: In this investigation, the roles of a TLP from Malus domestica (MdTLP7) in response to abiotic stresses were characterized by expressing it in Arabidopsis. The expression of wild-type full-length MdTLP7 (FL) significantly increased the stress tolerance of Arabidopsis seedlings to osmotic, salt, cold and heat stress, while the expression of truncated MdTLP7 containing only the tubby domain (Tub) also showed some function. Located on a central α helix surrounded by 12 anti-parallel ß strands in the tubby domain, the K190/R192 site may be involved in fixation to the plasma membrane, as shown by 3D homology modelling with animal TLPs. This site might play a crucial role in anti-stress functions since site-directed mutagenesis of MdTLP7 reduced stress tolerance. Subcellular localization showed that MdTLP7 was mainly localized in the plasma membrane in plant cells, suggesting that it might participate in the transduction of stress signals. CONCLUSIONS: The results of this study showed that MdTLP7 could improve abiotic stress tolerance not only in bacteria but also in plants. The K190/R192 residues in the tubby domain were not only the plasma membrane binding site of MdTLP7 but also played a key role in stress tolerance. These results may provide a basis for further exploring the mechanism of anti-stress functioning and downstream target genes of plant TLPs.


Assuntos
Arabidopsis/metabolismo , Malus/metabolismo , Proteínas de Plantas/metabolismo , Arabidopsis/fisiologia , Membrana Celular/metabolismo , Escherichia coli , Regulação da Expressão Gênica de Plantas , Malus/fisiologia , Microrganismos Geneticamente Modificados , Pressão Osmótica , Proteínas de Plantas/fisiologia , Plantas Geneticamente Modificadas , Estresse Salino , Estresse Fisiológico
20.
J Clin Lab Anal ; 31(6)2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28124804

RESUMO

BACKGROUND: High admission cholesterol has been associated with better outcome after acute ischaemic stroke (AIS), but a paradox not completely illustrated. The purpose of this study was to investigate the effect of the total cholesterol to high-density lipoprotein cholesterol (TC/HDL-C) on short-term survival after AIS. METHODS: Consecutive patients admitted in 2013 and 2015 were enrolled in the present study. The logistic regression analysis was conducted to evaluate predictors of 3-month outcomes. The primary endpoint was death. Secondary endpoint was good (modified Rankin Scale score 0-2 or equal to prestrike modified Rankin Scale score) at 3 months. RESULTS: Of 871 patients enrolled in the final analysis, 94 (10.8%) individuals died during 3 months of observation. The serum TC and TC/HDL-C levels at admission were significantly associated with stroke outcomes at 3 months, and the HDL-C level was only correlated with the good outcomes at 3 months. Mortality risk was markedly decreased for patients with high TC/HDL-C ratio (odds ratio: 0.23, 95% confidence interval [CI]: 0.10-0.50 for Q4:Q1; P-trend <.001) after adjustment. The effect of TC/HDL-C ratio on the probability of good outcomes was still obvious (odds ratio: 2.18, 95% CI: 1.40-3.39 for Q4:Q1; P-trend=.029). According to the receiver operating characteristic analyses, the best discriminating factor was a TG/HDL-C ≥3.37 (area under the ROC curve [AUC]=0.643, sensitivity 61.3%, specificity 61.7%) as well as the TC/HDL-C ≥4.09 for good outcomes (AUC: 0.587, sensitivity 63.9%, specificity 79.7%). CONCLUSIONS: High TC/HDL-C ratio may be associated with increased short-term survival and better outcomes after AIS.


Assuntos
HDL-Colesterol/sangue , Colesterol/sangue , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/mortalidade , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Curva ROC , Acidente Vascular Cerebral/epidemiologia , Resultado do Tratamento
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