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1.
Am J Surg ; 229: 65-75, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38065723

RESUMO

BACKGROUND: High rates of postoperative infection persist after different surgical procedures, encompassing surgical site infections (SSIs), remote infections, sepsis, and septic shock. Our aim was to assess presepsin's diagnostic accuracy for postoperative infections in patients across surgical procedures. METHOD: We conducted a comprehensive search in seven databases, extracting data independently. Using STATA 14.0, we calculated pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and Under the receiver operator curve and 95 â€‹% confidence interval (AUC, 95 â€‹% CI) as primary outcomes, with secondary outcomes involving sensitivity and specificity in subgroup analyses. RESULTS: This meta-analysis of 14 studies (1891 cases) evaluated presepsin's diagnostic value for postoperative infectious complications. Results include sensitivity of 77 â€‹% (70-83), specificity of 81 â€‹% (71-88), DOR of 14 (8-26), AUC of 84 (80-87), PLR of 4 (3-6), and NLR of 0.28 (0.21-0.38). Presepsin exhibits promise as a diagnostic tool for postoperative infections. CONCLUSION: In summary, compared to conventional markers like C-reactive protein (CRP) and procalcitonin (PCT), presepsin demonstrated superior sensitivity and specificity for detecting postoperative infectious complications across various surgical procedures.


Assuntos
Receptores de Lipopolissacarídeos , Sepse , Humanos , Biomarcadores , Proteína C-Reativa/metabolismo , Receptores de Lipopolissacarídeos/análise , Fragmentos de Peptídeos/análise , Sepse/diagnóstico , Sepse/epidemiologia , Sepse/etiologia
2.
Surg Infect (Larchmt) ; 24(9): 763-772, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37944095

RESUMO

Background: Post-operative infection remains a major cause of morbidity and mortality in adults early after liver transplantation (LT). Procalcitonin (PCT) may be a good test method for early diagnosis of post-operative infection and determining its severity. This study was performed to assess the diagnostic accuracy of PCT as a biomarker for infection after LT. Patients and Methods: A meta-analysis and systematic review was conducted for studies reporting diagnostic performance of PCT for infection in adults after LT. Observational studies were evaluated for their reporting of diagnostic accuracy, relevance, and quality. Results: Ten eligible studies assessing 730 patients were included in this meta-analysis and systematic review summarizing the diagnostic value of PCT for post-operative infection in adult liver transplantation. Pooled sensitivity and specificity with corresponding 95% confidence interval were 69% (95% confidence interval [CI], 54-81; heterogeneity I2 = 82.4%) and 88% (95% CI, 82-92; I2 = 52.7%), respectively. The diagnostic odd ratio (DOR) was 16 (95% CI, 10-25; I2 = 76.4%). The summary receiver operator characteristic (SROC) of PCT for post-operative infection was 0.88. There was a wide range of variability in the cutoff values, ranging from 0.22 to 42.80 ng/mL. Heterogeneity was reduced by excluding studies that focused on pediatric LT recipients. Conclusions: Procalcitonin is a moderately accurate diagnostic marker for post-operative infection in adult LT. Additionally, the diagnostic performance can be improved by combining it with other inflammatory biomarkers. This article provides the research direction for post-operative infection control.


Assuntos
Transplante de Fígado , Pró-Calcitonina , Humanos , Adulto , Criança , Transplante de Fígado/efeitos adversos , Biomarcadores , Sensibilidade e Especificidade , Complicações Pós-Operatórias/diagnóstico , Curva ROC
3.
J Intensive Care ; 11(1): 11, 2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36941674

RESUMO

BACKGROUND: Acute kidney injury (AKI) is a frequent syndrome in the intensive care unit (ICU). AKI patients with kidney function recovery have better short-term and long-term prognoses compared with those with non-recovery. Numerous studies focus on biomarkers to distinguish them. To better understand the predictive performance of urinary biomarkers of renal recovery in patients with AKI, we evaluated C-C motif chemokine ligand 14 (CCL14) and two first-generation biomarkers (cell cycle arrest biomarkers and neutrophil gelatinase-associated lipocalin) in two ICU settings. METHODS: We performed a prospective study to analyze urinary biomarkers for predicting renal recovery from AKI. Patients who developed AKI after ICU admission were enrolled and urinary biomarkers including tissue inhibitor of metalloproteinase-2 (TIMP-2), insulin-like growth factor-binding protein 7 (IGFBP7), CCL14, and neutrophil gelatinase-associated lipocalin (NGAL) were detected on the day of AKI diagnosis. The primary endpoint was non-recovery from AKI within 7 days. The individual discriminative ability of CCL14, [TIMP-2] × [IGFBP7] and NGAL to predict renal non-recovery were evaluated by the area under receiver operating characteristics curve (AUC). RESULTS: Of 164 AKI patients, 64 (39.0%) failed to recover from AKI onset. CCL14 showed a fair prediction ability for renal non-recovery with an AUC of 0.71 (95% CI 0.63-0.77, p < 0.001). [TIMP-2] × [IGFBP7] showed the best prediction for renal non-recovery with an AUC of 0.78 (95% CI 0.71-0.84, p < 0.001). However, NGAL had no use in predicting non-recovery with an AUC of 0.53 (95% CI 0.45-0.60, p = 0.562). A two-parameter model (non-renal SOFA score and AKI stage) predicted renal non-recovery with an AUC of 0.77 (95% CI 0.77-0.83, p = 0.004). When [TIMP-2] × [IGFBP7] was combined with the clinical factors, the AUC was significantly improved to 0.82 (95% CI 0.74-0.87, p = 0.049). CONCLUSIONS: Urinary CCL14 and [TIMP-2] × [IGFBP7] were fair predictors of renal non-recovery from AKI. Combing urinary [TIMP-2] × [IGFBP7] with a clinical model consisting of non-renal SOFA score and AKI stage enhanced the predictive power for renal non-recovery. Urinary CCL14 showed no significant advantage in predicting renal non-recovery compared to [TIMP-2] × [IGFBP7].

4.
Front Cell Infect Microbiol ; 12: 1045636, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36519133

RESUMO

Introduction: Sepsis is a life-threatening condition, and biomarkers are needed to diagnose sepsis fast and accurately. We aimed to perform this meta-analysis to investigate the diagnostic value of calprotectin on sepsis in critically ill patients. Methods: The investigators searched MEDLINE, Embase, Web of Science and Cochrane Library. Studies were included if they assessed the diagnostic accuracy of serum calprotectin for sepsis in intensive care unit (ICU). We estimated its diagnostic value and explored the source of heterogeneity. The bivariate model and the hierarchical summary receiver operating characteristic (HSROC) curve were used in the meta-analysis. Results: Six records assessing 821 patients were included in this meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio (PLR), and diagnostic odds ratio (DOR) were separately as 0.77, 0.85, 5.20, 0.27, respectively. The Fagan's nomogram showed post-test probabilities of 91% and 35% for positive and negative outcomes, respectively. Subgroup analysis indicated that sepsis definition could be a possible source of heterogeneity, but there's no sufficient data to investigate sepsis-3 definition. Sensitivity analysis suggested that two studies could affect the stability of pooled results. Conclusion: On the basis of our meta-analysis, calprotectin is a helpful marker for early diagnosis of sepsis on ICU admission.


Assuntos
Complexo Antígeno L1 Leucocitário , Sepse , Humanos , Sepse/diagnóstico , Curva ROC , Biomarcadores , Estado Terminal , Sensibilidade e Especificidade
5.
Front Surg ; 9: 1026586, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36311930

RESUMO

Background: Early allograft dysfunction (EAD) is a common postliver transplant complication that has been associated with graft failure and risk for poor prognosis. There are many risk factors for the incidence of EAD after liver transplantation (LT). This study investigated whether elevated postoperative myoglobin (Mb) increases the incidence of EAD in liver transplanted recipients. Methods: A total of 150 adult recipients who measured Mb within 3 days after liver transplantation between June 2019 and June 2021 were evaluated. Then, all patients were divided into two groups: the EAD group and the non-EAD group. Univariate and multivariate logistic regression analyses were performed, and receiver operating characteristic curves (ROCs) were constructed. Results: The incidence of EAD was 53 out of 150 patients (35.3%) in our study. Based on the multivariate logistic analysis, the risk of EAD increased with elevated postoperative Mb (OR = 1.001, 95% CI 1.000-1.001, P = 0.002). The Mb AUC was 0.657, and it was 0.695 when combined with PCT. When the subgroup analysis was conducted, the AUC of serum Mb prediction was better in patients whose preoperative model for end-stage liver disease score ≤ 15 or operative time ≥ 10 h (AUC = 0.751, 0.758, respectively, or 0.760, 0.800 when combined with PCT). Conclusion: Elevated Mb significantly increased the risk of postoperative EAD, suggesting that postoperative Mb may be a novel predictor of EAD after liver transplantation.The study was registered in the Chinese Clinical Trial Registry (Registration number: ChiCTR2100044257, URL: http://www.chictr.org.cn).

6.
Bosn J Basic Med Sci ; 22(6): 882-893, 2022 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-35535600

RESUMO

The ameliorative effects of α7 nicotinic acetylcholine receptor (α7nAChR) agonists have been demonstrated in acute kidney injury (AKI) caused by multiple stimulations. However, the ameliorative effect of α7nAChR on sepsis-induced acute kidney injury (SAKI) in the cecal ligation and puncture (CLP) model is unclear. Previous studies have demonstrated that α7nAChR is highly expressed on the surface of CD4+CD25+ regulatory T cells (Tregs). However, the role of Tregs in SAKI is unclear. We hypothesized that Tregs might play a role in the ameliorative effect of α7nAChR on SAKI. Hence, in this study, we determined the effects of PNU-282987 (a selective α7nAchR agonist) on SAKI and evaluated whether PNU-282987 would attenuate SAKI via regulating Tregs. Our study showed that immediate administration of PNU-282987 after CLP surgery in rats improved renal function, reduced levels of systemic inflammatory factors (tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), etc.), inflammatory cell infiltration and tubular apoptosis in renal tissues, and increased forkhead/winged helix transcription factor p3 (Foxp3) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) expression indicating activated Tregs. Moreover, in in vitro experiments, isolated Tregs co-cultured with PNU-282987 also displayed enhanced expression of CTLA-4 and Foxp3. Furthermore, Tregs were co-cultured with PNU-282987 for 24 hours and then reinfused into rats through the tail vein immediately after CLP surgery, and a significant renal protective effect was observed 24 hours postoperatively. These results demonstrate that PNU-282987 exerts its renal protective effects on SAKI through activation of Tregs.


Assuntos
Injúria Renal Aguda , Sepse , Ratos , Animais , Linfócitos T Reguladores/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/agonistas , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Antígeno CTLA-4/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Interleucina-6/metabolismo , Sepse/complicações , Sepse/metabolismo , Injúria Renal Aguda/tratamento farmacológico , Injúria Renal Aguda/etiologia , Fatores de Transcrição Forkhead/metabolismo , Fatores de Transcrição Winged-Helix/metabolismo
7.
Ann Intensive Care ; 12(1): 14, 2022 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-35150348

RESUMO

BACKGROUND: Acute kidney injury (AKI) is a common disease in the intensive care unit (ICU). AKI patients with nonrecovery of renal function have a markedly increased risk of death compared with patients with recovery. The current study aimed to explore and validate the utility of urinary cell cycle arrest biomarkers for predicting nonrecovery in patients who developed AKI after ICU admission. METHODS: We prospectively and consecutively enrolled 379 critically ill patients who developed AKI after admission to the ICU, which were divided into a derivation cohort (194 AKI patients) and a validation cohort (185 AKI patients). The biomarkers of urinary tissue inhibitor of metalloproteinase-2 (TIMP-2) and insulin-like growth factor-binding protein 7 (IGFBP7) were detected at inclusion immediately after AKI diagnosis (day 0) and 24 h later (day 1). The optimal cut-off values of these biomarkers for predicting nonrecovery were estimated in the derivation cohort, and their predictive accuracy was assessed in the validation cohort. The primary endpoint was nonrecovery from AKI (within 7 days). RESULTS: Of 379 patients, 159 (41.9%) patients failed to recover from AKI onset, with 79 in the derivation cohort and 80 in the validation cohort. Urinary [TIMP-2]*[IGFBP7] on day 0 showed a better prediction ability for nonrecovery than TIMP-2 and IGFBP7 alone, with an area under the reciever operating characteristic curve (AUC) of 0.751 [95% confidence interval (CI) 0.701-0.852, p < 0.001] and an optimal cut-off value of 1.05 ((ng/mL)2/1000). When [TIMP-2]*[IGFBP7] was combined with the clinical factors of AKI diagnosed by the urine output (UO) criteria, AKI stage 2-3 and nonrenal SOFA score for predicting nonrecovery, the AUC was significantly improved to 0.852 (95% CI 0.750-0.891, p < 0.001), which achieved a sensitivity and specificity of 88.8% (72.9, 98.7) and 92.6% (80.8, 100.0), respectively. However, urine [TIMP-2]*[IGFBP7], TIMP-2 alone, and IGFBP7 alone on day 1 performed poorly for predicting AKI recovery. CONCLUSION: Urinary [TIMP-2]*[IGFBP7] on day 0 showed a fair performance for predicting nonrecovery from AKI. The predictive accuracy can be improved when urinary [TIMP-2]*[IGFBP7] is combined with the clinical factors of AKI diagnosed by the UO criteria, AKI stage 2-3 and nonrenal SOFA score.

8.
Ann Palliat Med ; 10(11): 11265-11277, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34670383

RESUMO

BACKGROUND: Acute kidney injury (AKI) is a common and multifactorial complication after liver transplantation (LT). Myoglobin (Mb) which can be served as O2 storage and delivery depot is present in muscles and cardiac myocytes. Previous studies had shown the close relationship between Mb and AKI. But there is a lack of clinical studies for Mb with the risk of AKI due to LT. This study was performed to determine the association between the serum level of Mb and incidence of AKI in patients underwent LT. METHODS: The clinical data of 140 consecutive adult patients who underwent LT at our center from June 2018 to August 2020 were analyzed in this study. One hundred and fifteen patients met the inclusion criteria. The performances of postoperative laboratory variables (including serum Mb) were evaluated. The outcomes after LT, including the duration of intensive care unit (ICU) stay, hospital stay and 28-day mortality, were also measured. RESULTS: We divided 115 patients into AKI group (n=44) and non-AKI group (n=71). Serum Mb on post-operative day 0 (POD0) was significantly higher in AKI group than those in non-AKI group (P<0.001). According to univariate and multivariable logistic regression analysis, the levels of serum albumin (P=0.024), alanine transaminase (P=0.007) and Mb (P=0.006) on POD0 were independently associated with development of new AKI. The area under curve (AUC) of serum Mb after LT immediately had the best value for predicting AKI [AUC: 0.755, sensitivity: 63.6%, specificity: 77.3%, 95% confidence interval (CI): 0.661-0.849], its cut-off value was 957 ng/mL. CONCLUSIONS: Postoperative serum Mb was an independent risk factor for new AKI and could increase the accuracy of predicting the occurrence of post-LT AKI. TRIAL REGISTRATION: The study was registered in Chinese Clinical Trial Registry (registration number: ChiCTR2100044257).


Assuntos
Injúria Renal Aguda , Transplante de Fígado , Injúria Renal Aguda/etiologia , Adulto , Humanos , Tempo de Internação , Mioglobina , Complicações Pós-Operatórias , Estudos Retrospectivos , Fatores de Risco
9.
Front Plant Sci ; 12: 804356, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35003193

RESUMO

Tudor staphylococcal nucleases (TSNs) are evolutionarily conserved RNA binding proteins, which include redundant TSN1 and TSN2 in Arabidopsis. It has been showed TSNs are the components of stress granules (SGs) and regulate plant growth under salt stress. In this study, we find a binding protein of TSN1, RH31, which is a DEAD-box RNA helicase (RH). Subcellular localization studies show that RH31 is mainly located in the nucleus, but under salinity, it translocates to the cytoplasm where it accumulates in cytoplasmic granules. After cycloheximide (CHX) treatment which can block the formation of SGs by interfering with mRNP homeostasis, these cytoplasmic granules disappeared. More importantly, RH31 co-localizes with SGs marker protein RBP47. RH31 deletion results in salt-hypersensitive phenotype, while RH31 overexpression causes more resistant to salt stress. In summary, we demonstrate that RH31, the TSN1 binding protein, is a component of plant SGs and participates in regulation of salt-stress tolerance in Arabidopsis.

10.
Plant Physiol ; 184(1): 236-250, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32680974

RESUMO

Maintaining phosphorus (Pi) homeostasis in nodules is the key to nodule development and nitrogen fixation, an important source of nitrogen for agriculture and ecosystems. PHOSPHATE-TRANSPORTER1 (PHT1) and its regulator PHOSPHATE-STARVATION-RESPONSE1 (PHR1), which constitute the PHR1-PHT1 module, play important roles in maintaining Pi homeostasis in different organs. However, the PHR1-PHT1 module and its functions in nodules remain unknown. We identified one PHT1 (GmPHT1;11) and four PHR1 (GmPHR1) homologs in soybean (Glycine max) plants, which displayed specific expression patterns in different tissues in nodules, similar to previously reported GmPHT1;1 and GmPHT1;4 Through the integration of different approaches, GmPHR-GmPHT1 modules were confirmed. Combining our results and previous reports, we established multiple GmPHR-GmPHT1 modules acting in the infected or noninfected tissues in nodules. A single GmPHR had more than one GmPHT1 target, and vice versa. Therefore, overlapping and cross-talking modules monitored the wave of available Pi to maintain Pi homeostasis in nodules, which sequentially regulated nodule initiation and development. High levels of GmPHT1;11 enhanced Pi accumulation in nodules, increased nodule size, but decreased nodule number. Nitrogenase activity was also enhanced by GmPHT1;11 Our findings uncover GmPHR-GmPHT1 modules in nodules, which expands our understanding of the mechanism of maintaining Pi homeostasis in soybean plants.


Assuntos
Glycine max/metabolismo , Proteínas de Transporte de Fosfato/metabolismo , Fósforo/metabolismo , Proteínas de Plantas/metabolismo , Nódulos Radiculares de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas
11.
Oxid Med Cell Longev ; 2020: 1854206, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32509139

RESUMO

Acute lung injury (ALI) induced by paraquat (PQ) progresses rapidly with high mortality; however, there is no effective treatment, and the specific mechanism is not well understood. The antiaging protein klotho (KL) has multiple functions and exerts significant influences on various pathophysiological processes. This work evaluated the impact of KL on PQ-induced ALI and investigated its underlying mechanisms. As for in vivo research, C57BL/6 mice were treated with PQ (30 mg/kg) intraperitoneal (IP) injection to create a toxicity model of ALI (PQ group). The mice were divided into control group, KL group, PQ group, and PQ+KL group. For in vitro experiment, A549 cells were incubated with or without KL and then treated in the presence or absence of PQ for 24 h. In vivo result indicated that KL reduced the mortality, reduced IL-1ß and IL-6 in the bronchoalveolar lavage fluid (BALF), attenuated ALI, and decreased apoptosis in situ. In vitro result revealed that KL significantly improved cell viability, reduced the levels of IL-1ß and IL-6 in culture supernatants, suppressed cell apoptosis, inhibited caspase-3 activation, and enhanced mitochondrial membrane potential (ΔΨm) after PQ treatment. Besides, KL effectively abated reactive oxygen species (ROS) production, improved GSH content, and lowered lipid peroxidation in PQ-exposed A549 cells. Further experiments indicated that phosphorylated JNK and P38 MAPK was increased after PQ treatment; however, KL pretreatment could significantly lower the phosphorylation of P38 MAPK. Suppression of P38 MAPK improved cell viability, alleviated inflammatory response, and reduced apoptosis-related signals; however, it had no obvious effect on the production of ROS. Treatment with N-acetylcysteine (NAC), a classic ROS scavenger, could suppress ROS production and P38 MAPK activation. These findings suggested that KL could alleviate PQ-caused ALI via inhibiting ROS/P38 MAPK signaling-regulated inflammatory responses and mitochondria-dependent apoptosis.


Assuntos
Lesão Pulmonar Aguda/metabolismo , Envelhecimento/fisiologia , Glucuronidase/metabolismo , Células A549 , Animais , Apoptose , Modelos Animais de Doenças , Humanos , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Proteínas Klotho , Peroxidação de Lipídeos , Masculino , Potencial da Membrana Mitocondrial , Camundongos , Camundongos Endogâmicos C57BL , Paraquat , Transdução de Sinais , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
12.
J Exp Bot ; 71(4): 1375-1386, 2020 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-31701139

RESUMO

As one of the most important events during the life cycle of flowering plants, the floral transition is of crucial importance for plant propagation and requires the precise coordination of multiple endogenous and external signals. There have been at least four flowering pathways (i.e. photoperiod, vernalization, gibberellin, and autonomous) identified in Arabidopsis. We previously reported that two Arabidopsis RNA-binding proteins, KHZ1 and KHZ2, redundantly promote flowering. However, the underlying mechanism was unclear. Here, we found that the double mutant khz1 khz2 flowered late under both long-day and short-day conditions, but responded to vernalization and gibberellin treatments. The late-flowering phenotype was almost completely rescued by mutating FLOWERING LOCUS C (FLC) and fully rescued by overexpressing FLOWERING LOCUS T (FT). Additional experiments demonstrated that the KHZs could form homodimers or interact to form heterodimers, localized to nuclear dots, and repressed the splicing efficiency of FLC pre-mRNA. Together, these data indicate that the KHZs could promote flowering via the autonomous pathway by repressing the splicing efficiency of FLC pre-mRNA.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Flores/genética , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Domínio MADS/genética , Proteínas de Domínio MADS/metabolismo , Mutação , Precursores de RNA/genética
13.
Chemistry ; 24(7): 1651-1656, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29168912

RESUMO

Transition-metal oxides are one of the most promising anode materials for energy storage in lithium- and sodium-ion batteries (LIBs and NIBs, respectively). To improve the electrochemical performance of metal oxides (e.g., Co3 O4 ), such as capacity and cyclability, a convenient strategy (with a metal-organic framework as a template) is introduced to generate Zn- or Ni-doped Co3 O4 . The obtained hollow core-shell nanosized Co3 O4 (denoted as Zn/Ni-Co-Oxide) derived from pyrolyzing zinc or nickel co-doped ZIF-67 (Co(mIm)2 ; mIm=methylimidazole) shows a drastically enhanced capacity of 1300 mAh g-1 at a high current density of 5000 mA g-1 , compared with that of pristine cobalt oxide (800 mAh g-1 ) in LIBs. A zinc-doped Zn-Co-Oxide demonstrates a stable capacity of 1600 mAh g-1 at 1000 mA g-1 for 700 cycles and an excellent performance in full coin cells (cycled with LiNi0.5 Co0.3 Mn0.2 O2 ). Moreover, NIB tests show a stable capacity of 300 mAh g-1 for more than 250 cycles.

14.
Plant Mol Biol ; 95(6): 549-565, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29076025

RESUMO

KEY MESSAGE: The two novel CCCH zinc-finger and K-homolog (KH) proteins, KHZ1 and KHZ2, play important roles in regulating flowering and senescence redundantly in Arabidopsis. The CCCH zinc-finger proteins and K-homolog (KH) proteins play important roles in plant development and stress responses. However, the biological functions of many CCCH zinc-finger proteins and KH proteins remain uncharacterized. In Arabidopsis, KHZ1 and KHZ2 are characterized as two novel CCCH zinc-finger and KH domain proteins which belong to subfamily VII in CCCH family. We obtained khz1, khz2 mutants and khz1 khz2 double mutants, as well as overexpression (OE) lines of KHZ1 and KHZ2. Compared with the wild type (WT), the khz2 mutants displayed no defects in growth and development, and the khz1 mutants were slightly late flowering, whereas the khz1 khz2 double mutants showed a pronounced late flowering phenotype. In contrast, artificially overexpressing KHZ1 and KHZ2 led to the early flowering. Consistent with the late flowering phenotype, the expression of flowering repressor gene FLC was up-regulated, while the expression of flowering integrator and floral meristem identity (FMI) genes were down-regulated significantly in khz1 khz2. In addition, we also observed that the OE plants of KHZ1 and KHZ2 showed early leaf senescence significantly, whereas the khz1 khz2 double mutants showed delayed senescence of leaf and the whole plant. Both KHZ1 and KHZ2 were ubiquitously expressed throughout the tissues of Arabidopsis. KHZ1 and KHZ2 were localized to the nucleus, and possessed both transactivation activities and RNA-binding abilities. Taken together, we conclude that KHZ1 and KHZ2 have redundant roles in the regulation of flowering and senescence in Arabidopsis.


Assuntos
Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/fisiologia , Flores/fisiologia , Desenvolvimento Vegetal , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/metabolismo , Dedos de Zinco , Sequência de Aminoácidos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Sequência de Bases , Núcleo Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Mutação/genética , Fenótipo , Fotoperíodo , Desenvolvimento Vegetal/genética , Plantas Geneticamente Modificadas , Ligação Proteica , Domínios Proteicos , RNA de Plantas/metabolismo , Proteínas de Ligação a RNA/genética , Homologia de Sequência de Aminoácidos , Frações Subcelulares/metabolismo , Fatores de Tempo , Ativação Transcricional/genética
15.
Plant Physiol ; 175(4): 1703-1719, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29066667

RESUMO

In plants, the posttranslational modification small ubiquitin-like modifier (SUMO) is involved in regulating several important developmental and cellular processes, including flowering time control and responses to biotic and abiotic stresses. Here, we report two proteases, SUMO PROTEASE RELATED TO FERTILITY1 (SPF1) and SPF2, that regulate male and female gamete and embryo development and remove SUMO from proteins in vitro and in vivo. spf1 mutants exhibit abnormal floral structures and embryo development, while spf2 mutants exhibit largely a wild-type phenotype. However, spf1 spf2 double mutants exhibit severe abnormalities in microgametogenesis, megagametogenesis, and embryo development, suggesting that the two genes are functionally redundant. Mutation of SPF1 and SPF2 genes also results in misexpression of generative- and embryo-specific genes. In vitro, SPF1 and SPF2 process SUMO1 precursors into a mature form, and as expected in vivo, spf1 and spf2 mutants accumulate SUMO conjugates. Using a yeast two-hybrid screen, we identified EMBRYO SAC DEVELOPMENT ARREST9 (EDA9) as an SPF1-interacting protein. In vivo, we demonstrate that EDA9 is sumolyated and that, in spf1 mutants, EDA9-SUMO conjugates increase in abundance, demonstrating that EDA9 is a substrate of SPF1. Together, our results demonstrate that SPF1 and SPF2 are two SUMO proteases important for plant development in Arabidopsis (Arabidopsis thaliana).


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação Enzimológica da Expressão Gênica/fisiologia , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Plantas/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Ligação a DNA/genética , Mutação , Proteínas de Plantas/genética , Pólen/genética , Pólen/fisiologia , Reprodução/genética , Reprodução/fisiologia
16.
Chemistry ; 23(48): 11513-11518, 2017 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-28707378

RESUMO

A thin layer of a highly porous metal-organic framework material, ZIF-8, is fabricated uniformly on the surface of nanostructured transition metal oxides (ZnO nanoflakes and MnO2 nanorods) to boost the transfer of lithium ions. The novel design and uniform microstructure of the MOF-coated TMOs (ZIF-8@TMOs) exhibit dramatically enhanced rate and cycling performance comparing to their pristine counterparts. The capacities of ZIF-8@ZnO (nanoflakes) and ZIF-8@MnO2 (nanorods) are 28 % and 31 % higher that of the pristine ones at the same current density. The nanorods of ZIF-8@MnO2 show a capacity of 1067 mAh g-1 after 500 cycles at 1 Ag-1 and without any fading. To further improve the conductivity and capacity, the ZIF-8-coated materials are pyrolyzed at 700 °C in an N2 atmosphere (ZIF-8@TMO-700 N). After pyrolysis, a much higher capacity improvement is achieved: ZIF-8@ZnO-700 N and ZIF-8@MnO2 -700 N have 54 % and 69 % capacity increases compared with the pristine TMOs, and at 1 Ag-1 , the capacity of ZIF-8@MnO2 -700 N is 1060 mAh g-1 after cycling for 300 cycles.

17.
Front Plant Sci ; 8: 981, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28642780

RESUMO

The exosome complex plays a central and essential role in RNA metabolism. However, current research on functions of exosome subunit in plants is limited. Here, we used an egg cell-specific promoter-controlled CRISPR/Cas9 system to knock out RRP42 which encodes a core subunit of the Arabidopsis exosome and presented evidence that RRP42 is essential for the development of female gametophytes. Next, we designed three different amiRNAs targeting RRP42. The rrp42 knock-down mutants mainly displayed variegated and serrated leaves, especially in cauline leaves. The internal anatomy of cauline leaves displayed irregularly shaped palisade cells and a reduced density of mesophyll cells. Interestingly, we detected highly accumulated mRNAs that encode xyloglucan endotransglucosylase/hydrolases (XTHs) and expansins (EXPAs) during later growth stages in rrp42 knock-down mutants. The mRNA decay kinetics analysis for XTH19, EXPA10, and EXPA11 revealed that RRP42 had a role in the decay of these mRNAs in the cytoplasm. RRP42 is localized to both the nucleus and cytoplasm, and RRP42 is preferentially expressed in cauline leaves during later growth stages. Altogether, our results demonstrate that RRP42 is essential for the development of female gametophytes and plays an important role in mesophyll cell morphogenesis.

18.
BMJ Open ; 7(6): e013105, 2017 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-28647719

RESUMO

OBJECTIVES: The purpose of the present study was to explore the characteristics of workplace violence that Chinese nurses at tertiary and county-level hospitals encountered in the 12 months from December 2014 to January 2016, to identify and analyse risk factors for workplace violence, and to establish the basis for future preventive strategies. DESIGN: A cross-sectional study. SETTING: A total of 44 tertiary hospitals and 90 county-level hospitals in 16 provinces (municipalities or autonomous regions) in China. METHODS: We used stratified random sampling to collect data from December 2014 to January 2016. We distributed 21 360 questionnaires, and 15 970 participants provided valid data (effective response rate=74.77%). We conducted binary logistic regression analyses on the risk factors for workplace violence among the nurses in our sample and analysed the reasons for aggression. RESULTS: The prevalence of workplace violence was 65.8%; of this, 64.9% was verbal violence, and physical violence and sexual harassment accounted for 11.8% and 3.9%, respectively. Frequent workplace violence occurred primarily in emergency and paediatric departments. Respondents reported that patients' relatives were the main perpetrators in tertiary and county-level hospitals. Logistic regression analysis showed that respondents' age, department, years of experience and direct contact with patients were common risk factors at different levels of hospitals. CONCLUSIONS: Workplace violence is frequent in China's tertiary and county-level hospitals; its occurrence is especially frequent in the emergency and paediatric departments. It is necessary to cope with workplace violence by developing effective control strategies at individual, hospital and national levels.


Assuntos
Hospitais , Recursos Humanos de Enfermagem Hospitalar , Abuso Físico/estatística & dados numéricos , Assédio Sexual/estatística & dados numéricos , Violência no Trabalho/estatística & dados numéricos , Adaptação Psicológica , Adulto , China/epidemiologia , Estudos Transversais , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Fatores de Risco , Autorrelato
19.
J Am Chem Soc ; 139(12): 4258-4261, 2017 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-28316238

RESUMO

Covalent organic frameworks (COFs) have attracted growing interest by virtue of their structural diversity and tunability. Herein, we present a novel approach for the development of organic rechargeable battery cathodes in which three distinct redox-active COFs were successfully prepared and delaminated into 2D few-layer nanosheets. Compared with the pristine COFs, the exfoliated COFs with shorter Li+ diffusion pathways allow a significant higher utilization efficiency of redox sites and faster kinetics for lithium storage. Unlike diffusion-controlled manners in the bulk COFs, the redox reactions in ECOFs are mainly dominated by charge transfer process. The capacity and potential are further engineered by reticular design of COFs without altering the underlying topology. Specifically, DAAQ-ECOF exhibits excellent rechargeability (98% capacity retention after 1800 cycles) and fast charge-discharge ability (74% retention at 500 mA g-1 as compared to at 20 mA g-1). DABQ-ECOF shows a specific capacity of 210 mA h g-1 and a voltage plateau of 2.8 V.

20.
Sci Bull (Beijing) ; 62(13): 965-970, 2017 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-36659468

RESUMO

The chemical structure evolution of coal, which is important for understanding coalification and the accompanying volatile and possible oil generation, is generally thought to be influenced by temperature, time and confining pressure. Though evidence concerning the impacts of stress on the chemical structure has accumulated for many years and some hypotheses have been proposed, the mechanism remains controversial. Recent years have seen a breakthrough in mechanochemistry, which proves that stress can act on the molecule directly to initiate or accelerate reactions by deforming the chemical bonds. The progress in mechanochemistry gives researchers incentive to consider how stress works on the chemical structure of coals. Preliminary quantum chemical calculations have been performed on the macromolecule of anthracite to explain the mechanism of gas generation during the deformation experiments at low temperatures. This paper briefly reviews the evidence regarding the impacts of stress on the chemical structure of coals and introduces the recent achievements in the mechanism research. To further investigate this problem, more work should be undertaken by researchers from both geology and quantum chemistry fields.

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