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1.
Small ; : e2403292, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38958094

RESUMO

Antimony selenide (Sb2Se3) has sparked significant interest in high-efficiency photovoltaic applications due to its advantageous material and optoelectronic properties. In recent years, there has been considerable development in this area. Nonetheless, defects and suboptimal [hk0] crystal orientation expressively limit further device efficiency enhancement. This study used Zinc (Zn) to adjust the interfacial energy band and strengthen carrier transport. For the first time, it is discovered that the diffusion of Zn in the cadmium sulfide (CdS) buffer layer can affect the crystalline orientation of the Sb2Se3 thin films in the superstrate structure. The effect of Zn diffusion on the morphology of Sb2Se3 thin films with CdxZn1-xS buffer layer has been investigated in detail. Additionally, Zn doping promotes forming Sb2Se3 thin films with the desired [hk1] orientation, resulting in denser and larger grain sizes which will eventually regulate the defect density. Finally, based on the energy band structure and high-quality Sb2Se3 thin films, this study achieves a champion power conversion efficiency (PCE) of 8.76%, with a VOC of 458 mV, a JSC of 28.13 mA cm-2, and an FF of 67.85%. Overall, this study explores the growth mechanism of Sb2Se3 thin films, which can lead to further improvements in the efficiency of Sb2Se3 solar cells.

2.
New Phytol ; 241(4): 1435-1446, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37997699

RESUMO

Our ability to predict temperature responses of leaf respiration in light and darkness (RL and RDk ) is essential to models of global carbon dynamics. While many models rely on constant thermal sensitivity (characterized by Q10 ), uncertainty remains as to whether Q10 of RL and RDk are actually similar. We measured short-term temperature responses of RL and RDk in immature and mature leaves of two evergreen tree species, Castanopsis carlesii and Ormosia henry in an open field. RL was estimated by the Kok method, the Yin method and a newly developed Kok-iterCc method. When estimated by the Yin and Kok-iterCc methods, RL and RDk had similar Q10 (c. 2.5). The Kok method overestimated both Q10 and the light inhibition of respiration. RL /RDk was not affected by leaf temperature. Acclimation of respiration in summer was associated with a decline in basal respiration but not in Q10 in both species, which was related to changes in leaf nitrogen content between seasons. Q10 of RL and RDk in mature leaves were 40% higher than in immature leaves. Our results suggest similar Q10 values can be used to model RL and RDk while leaf development-associated changes in Q10 require special consideration in future respiration models.


Assuntos
Fotossíntese , Respiração , Temperatura , Escuridão , Estações do Ano , Folhas de Planta
3.
J Am Chem Soc ; 145(9): 5496-5505, 2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36812021

RESUMO

Achieving transition-metal-catalyzed reactions of diene-ynes/diene-enes and carbon monoxide (CO) to deliver [4 + 2 + 1] cycloadducts, rather than the kinetically favored [2 + 2 + 1] products, is challenging. Here, we report that this can be solved by adding a cyclopropyl (CP) cap to the diene moiety of the original substrates. The resulting CP-capped diene-ynes/diene-enes can react with CO under Rh catalysis to give [4 + 2 + 1] cycloadducts exclusively without forming [2 + 2 + 1] products. This reaction has a broad scope and can be used to synthesize useful 5/7 bicycles with a CP moiety. Of the same importance, the CP moiety in the [4 + 2 + 1] cycloadducts can act as an intermediate group for further transformations so that other challenging bicyclic 5/7 and tricyclic 5/7/5, 5/7/6, and 5/7/7 skeletons, some of which are widely found in natural products, can be accessed. The mechanism of this [4 + 2 + 1] reaction has been investigated by quantum chemical calculations, and the role of the CP group in avoiding the possible side [2 + 2 + 1] reaction has been identified, showing that the [4 + 2 + 1] is controlled by releasing the ring strain in the methylenecyclopropyl (MCP) group (about 7 kcal/mol) in the CP-capped dienes.

4.
J Am Chem Soc ; 145(31): 17087-17095, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37523458

RESUMO

Transition-metal-catalyzed [4 + 1] reaction of dienes and carbon monoxide (CO) is the most straightforward and easily envisioned cyclization for the synthesis of five-membered carbocycles, which are ubiquitously found in natural products and functional molecules. Unfortunately, no test of this reaction was reported, and consequently, chemists do not know whether such kind of reaction works or not. Herein, we report that the [4 + 1] reaction of common dienes and CO cannot work, at least under the catalysis of [Rh(cod)Cl]2. However, using cyclopropyl-capped dienes (also named allylidenecyclopropanes) as substrates, the corresponding [4 + 1] reaction with CO proceeds smoothly in the presence of [Rh(cod)Cl]2. This [4 + 1] reaction, with a broad scope, provides efficient access to five-membered carbocyclic compounds of spiro[2.4]hept-6-en-4-ones. The [4 + 1] cycloadducts can be further transformed into other molecules by using the unique chemistry of cyclopropyl groups present in these molecules. The mechanism of this [4 + 1] reaction has been investigated by quantum chemical calculations, uncovering that cyclopropyl-capped dienes are strained dienes and the oxidative cyclization step in the [4 + 1] catalytic cycle can release this (angular) strain both kinetically and thermodynamically. The strain release in this step then propagates to all followed CO coordination/CO insertion/reductive elimination steps in the [4 + 1] catalytic cycle, helping the realization of this cycloaddition reaction. In contrast, common dienes (including cyclobutyl-capped dienes) do not have such advantages and their [4 + 1] reaction suffers from energy penalty in all steps involved in the [4 + 1] catalytic cycle. The reactivity of ene-allenes for the [4 + 1] reaction with CO is also discussed.

5.
Small ; 19(48): e2302704, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37605327

RESUMO

Patients with osteoporotic fractures often require effective fixation and subsequent bone repair. However, currently available materials are often limited functionally, failing to improve this cohort's outcomes. Herein, kaempferol-loaded mesoporous bioactive glass nanoparticles (MBGNs)-doped orthopedic adhesives are prepared to assist osteoporotic fracture fixation and restore dysregulated bone homeostasis, including promoting osteoblast formation while inhibiting osteoclastic bone-resorbing activity to synergistically promote osteoporotic fracture healing. The injectability, reversible adhesiveness and malleable properties endowed the orthopedic adhesives with high flexibility and hemostatic performance to adapt to complex clinical scenarios. Moreover, Ca2+ and SiO4 4- ions released from MBGNs can accelerate osteogenesis via the PI3K/AKT pathway, while kaempferol mediated osteoclastogenesis inhibition and can slow down the bone resorption process through NF-κB pathway, which regulated bone regeneration and remodeling. Importantly, implementing the orthopedic adhesive is validated as an effective closed-loop management approach in restoring the dysregulated bone homeostasis of osteoporotic fractures.


Assuntos
Fraturas por Osteoporose , Humanos , Fraturas por Osteoporose/terapia , Quempferóis/farmacologia , Adesivos , Fosfatidilinositol 3-Quinases , Osteogênese , Homeostase
6.
Plant Cell Environ ; 46(9): 2827-2840, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37278611

RESUMO

How root respiration acclimates to global warming remains unclear, especially in subtropical forests that play a key role in the global carbon budget. In a large-scale in situ soil warming experiment, the occurrence of, and mechanisms controlling over, the acclimation of fine-root respiration of Cunninghamia lanceolata during the fourth year of warming were investigated. Specific respiration rates (at reference temperature of 20°C; SRR20 ) were measured with exogenous glucose addition, uncoupler addition, or no addition, and root morphological and chemical traits were also measured. Warming decreased SRR20 by 18.4% only during summer, indicating partial thermal acclimation of fine-root respiration under warming. Warming did not change fine-root N concentration, showing no possible enzyme limitation on respiration. Warming decreased root soluble sugar/starch ratio in summer, and glucose addition increased respiration only under warming, indicating a warming-induced substrate limitation on respiration. Uncoupler addition also stimulated respiration only under warming, showing a warming-induced adenylate limitation on respiration. These findings suggest that thermal acclimation of root respiration in subtropical forests, which is at least partially constrained by substrate and adenylate use, is conducive to reducing ecosystem carbon emissions and mitigating the positive feedback between atmospheric CO2 and climate warming.


Assuntos
Ecossistema , Árvores , Solo , Temperatura , Glucose , Aquecimento Global , Respiração , Carbono
7.
Glob Chang Biol ; 29(14): 4081-4093, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37096422

RESUMO

It is widely accepted that phosphorus (P) limits microbial metabolic processes and thus soil organic carbon (SOC) decomposition in tropical forests. Global change factors like elevated atmospheric nitrogen (N) deposition can enhance P limitation, raising concerns about the fate of SOC. However, how elevated N deposition affects the soil priming effect (PE) (i.e., fresh C inputs induced changes in SOC decomposition) in tropical forests remains unclear. We incubated soils exposed to 9 years of experimental N deposition in a subtropical evergreen broadleaved forest with two types of 13 C-labeled substrates of contrasting bioavailability (glucose and cellulose) with and without P amendments. We found that N deposition decreased soil total P and microbial biomass P, suggesting enhanced P limitation. In P unamended soils, N deposition significantly inhibited the PE. In contrast, adding P significantly increased the PE under N deposition and by a larger extent for the PE of cellulose (PEcellu ) than the PE of glucose (PEglu ). Relative to adding glucose or cellulose solely, adding P with glucose alleviated the suppression of soil microbial biomass and C-acquiring enzymes induced by N deposition, whereas adding P with cellulose attenuated the stimulation of acid phosphatase (AP) induced by N deposition. Across treatments, the PEglu increased as C-acquiring enzyme activity increased, whereas the PEcellu increased as AP activity decreased. This suggests that P limitation, enhanced by N deposition, inhibits the soil PE through varying mechanisms depending on substrate bioavailability; that is, P limitation regulates the PEglu by affecting soil microbial growth and investment in C acquisition, whereas regulates the PEcellu by affecting microbial investment in P acquisition. These findings provide new insights for tropical forests impacted by N loading, suggesting that expected changes in C quality and P limitation can affect the long-term regulation of the soil PE.


Assuntos
Carbono , Solo , Solo/química , Nitrogênio/análise , Fósforo , Florestas , Microbiologia do Solo , Glucose
8.
BMC Musculoskelet Disord ; 24(1): 286, 2023 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-37055830

RESUMO

BACKGROUND: Hip arthroplasty (HA) is one of the most effective procedures for patients with hip fractures. The timing of surgery played a significant role in the short-term outcome for these patients, but conflicting evidence has been found. METHODS: The Nationwide Inpatient Sample database was investigated from 2002 to 2014 and identified 247,377 patients with hip fractures undergoing HA. The sample was stratified into ultra-early (0 day), early (1-2 days) and delayed (3-14 days) groups based on time to surgery. Yearly trends, postoperative surgical and medical complications, postoperative length of hospital stay (POS) and total costs were compared after propensity scores were matched between groups by demographics and comorbidity. RESULTS: From 2002 to 2014, the percentage of hip fracture patients who underwent HA increased from 30.61 to 31.98%. Early surgery groups showed fewer medical complications but higher surgical complications. However, specific complication evaluation showed both ultra-early and early groups decreased most of the surgery and medical complications with increasing post hemorrhagic anemia and fever. Medical complications were also reduced in the ultra-early group, but surgical complications increased. Early surgery groups reduced the POS by 0.90 to 1.05 days and total hospital charges by 32.6 to 44.9 percent than delayed surgery groups. Ultra-early surgery showed no benefit from POS than early group, but reduced total hospital charges by 12.2 percent. CONCLUSION: HA surgery performed within 2 days showed more beneficial effects on adverse events than delayed surgery. But surgeons should be cognizant of the potential increased risks of mechanical complications and post-hemorrhagic anemia.


Assuntos
Artroplastia de Quadril , Fraturas do Quadril , Humanos , Artroplastia de Quadril/efeitos adversos , Estudos Retrospectivos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/cirurgia , Fraturas do Quadril/epidemiologia , Fraturas do Quadril/cirurgia , Fraturas do Quadril/complicações , Pacientes Internados , Tempo de Internação
9.
J Med Internet Res ; 25: e45225, 2023 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-37862061

RESUMO

BACKGROUND: The global pandemics of severe acute respiratory syndrome, Middle East respiratory syndrome, and COVID-19 have caused unprecedented crises for public health. Coronaviruses are constantly evolving, and it is unknown which new coronavirus will emerge and when the next coronavirus will sweep across the world. Knowledge graphs are expected to help discover the pathogenicity and transmission mechanism of viruses. OBJECTIVE: The aim of this study was to discover potential targets and candidate drugs to repurpose for coronaviruses through a knowledge graph-based approach. METHODS: We propose a computational and evidence-based knowledge discovery approach to identify potential targets and candidate drugs for coronaviruses from biomedical literature and well-known knowledge bases. To organize the semantic triples extracted automatically from biomedical literature, a semantic conversion model was designed. The literature knowledge was associated and integrated with existing drug and gene knowledge through semantic mapping, and the coronavirus knowledge graph (CovKG) was constructed. We adopted both the knowledge graph embedding model and the semantic reasoning mechanism to discover unrecorded mechanisms of drug action as well as potential targets and drug candidates. Furthermore, we have provided evidence-based support with a scoring and backtracking mechanism. RESULTS: The constructed CovKG contains 17,369,620 triples, of which 641,195 were extracted from biomedical literature, covering 13,065 concept unique identifiers, 209 semantic types, and 97 semantic relations of the Unified Medical Language System. Through multi-source knowledge integration, 475 drugs and 262 targets were mapped to existing knowledge, and 41 new drug mechanisms of action were found by semantic reasoning, which were not recorded in the existing knowledge base. Among the knowledge graph embedding models, TransR outperformed others (mean reciprocal rank=0.2510, Hits@10=0.3505). A total of 33 potential targets and 18 drug candidates were identified for coronaviruses. Among them, 7 novel drugs (ie, quinine, nelfinavir, ivermectin, asunaprevir, tylophorine, Artemisia annua extract, and resveratrol) and 3 highly ranked targets (ie, angiotensin converting enzyme 2, transmembrane serine protease 2, and M protein) were further discussed. CONCLUSIONS: We showed the effectiveness of a knowledge graph-based approach in potential target discovery and drug repurposing for coronaviruses. Our approach can be extended to other viruses or diseases for biomedical knowledge discovery and relevant applications.


Assuntos
COVID-19 , Reposicionamento de Medicamentos , Humanos , Reconhecimento Automatizado de Padrão , Bases de Conhecimento , Unified Medical Language System
10.
J Craniofac Surg ; 34(2): 602-606, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36731109

RESUMO

Children with cleft lip/palate are usually faced with upper airway problems after surgical repair. The severity of upper airway obstruction is more likely associated with the age and preoperative diagnosis of obstructive sleep apnea (OSA). This study aimed to investigate the severity of OSA in toddlers before palatoplasty from the perspective of polysomnography. In this retrospective cohort study, 97 children with unrepaired cleft palate and habitual prone sleeping were identified with a mean age of 1.6 years (SD 0.6) and divided into 2 age groups (1.5 year or younger and older than 1.5 year). Detailed information was collected including demographics, sleep parameters, and respiratory disturbances. Polysomnography results showed these children were at high risks of OSA with averagely moderate severity at night during their early childhood [apnea-hypopnea index 7.2±3.2 events/hour; obstructive apnea index (OAI) 6.5±2.8 events/hour]. Positional OAI was greatly lower in prone than that in laterals or in supine. Far more sleep time was spent in prone than in supine (42.9%±42.2% versus 8.5%±15.7%), which were consistent with parental reporting of prone sleeping habits. There were no significant differences found between the 2 age groups in respiratory disturbances such as apnea-hypopnea index, OAI, mean oxygen saturation, and nadir oxygen saturation ( P =0.097-0.988). Thus, prone sleeping with a history of snoring might be indicators for early screening for OSA in the cleft population. Adequate attention should be paid to their upper airway and, if available, overnight polysomnography should be performed to ascertain their potential respiratory problems before repair surgery.


Assuntos
Fenda Labial , Fissura Palatina , Síndromes da Apneia do Sono , Apneia Obstrutiva do Sono , Humanos , Pré-Escolar , Lactente , Fissura Palatina/cirurgia , Fenda Labial/complicações , Estudos Retrospectivos , Sono
11.
Sensors (Basel) ; 23(10)2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37430882

RESUMO

With the promotion of Industry 4.0, which emphasizes interconnected and intelligent devices, several factories have introduced numerous terminal Internet of Things (IoT) devices to collect relevant data or monitor the health status of equipment. The collected data are transmitted back to the backend server through network transmission by the terminal IoT devices. However, as devices communicate with each other over a network, the entire transmission environment faces significant security issues. When an attacker connects to a factory network, they can easily steal the transmitted data and tamper with them or send false data to the backend server, causing abnormal data in the entire environment. This study focuses on investigating how to ensure that data transmission in a factory environment originates from legitimate devices and that related confidential data are encrypted and packaged. This paper proposes an authentication mechanism between terminal IoT devices and backend servers based on elliptic curve cryptography and trusted tokens with packet encryption using the TLS protocol. Before communication between terminal IoT devices and backend servers can occur, the authentication mechanism proposed in this paper must first be implemented to confirm the identity of the devices and, thus, the problem of attackers imitating terminal IoT devices transmitting false data is resolved. The packets communicated between devices are also encrypted, preventing attackers from knowing their content even if they steal the packets. The authentication mechanism proposed in this paper ensures the source and correctness of the data. In terms of security analysis, the proposed mechanism in this paper effectively withstands replay attacks, eavesdropping attacks, man-in-the-middle attacks, and simulated attacks. Additionally, the mechanism supports mutual authentication and forward secrecy. In the experimental results, the proposed mechanism demonstrates approximately 73% improvement in efficiency through the lightweight characteristics of elliptic curve cryptography. Moreover, in the analysis of time complexity, the proposed mechanism exhibits significant effectiveness.

12.
Angew Chem Int Ed Engl ; 62(12): e202217654, 2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-36598873

RESUMO

We report here computational evidence for a metalla-Claisen rearrangement (MCR) in the case of gold-catalyzed [4+2] cycloaddition reaction of yne-dienes. The [4+2] reaction starts from exo cyclopropanation, followed by MCR and reductive elimination. The cyclopropane moiety formed in the first step is crucial for a low barrier of the MCR step. In addition, the importance of an appropriate combination of the tether group and the terminal substituent on alkyne in the yne-diene substrates was studied. The mechanism of rhodium-catalyzed [4+2] reaction of yne-dienes was also investigated to see whether an MCR mechanism is involved or not. The findings and new understanding hereby reported represent an important advance in the catalysis field.

13.
Mol Genet Genomics ; 297(2): 553-559, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35212839

RESUMO

Nonsyndromic cleft lip with or without palate (NSCL/P) is a common birth defect involving genetic factors. We conducted this case-control study to verify the association of ten single-nucleotide polymorphisms (SNPs) of six genes (VAX1, MAFB, PAX7, ABCA4, NTN1, and NOG) with NSCL/P in the Chinese population. The study included 249 NSCL/P patients, 62 nonsyndromic cleft palate only (NSCPO) patients and 480 controls. Three loci, namely, VAX1 rs7078160, MAFB rs11696257, and NTN1 rs4791774, were associated with NSCL/P (Bonferroni method adjusted p values were 0.020, 0.00031, and 0.030, respectively). We also found that the disease risk of individuals carrying both VAX1 rs7078160 and NTN1 rs4791774 was higher than those carrying only one of them (p = 4.50 × 10-4 and 6.03 × 10-3, respectively). SNPs of genes VAX1 rs7078160, MAFB rs11696257, and NTN1 rs4791774 increased NSCL/P risk in the Chinese population.


Assuntos
Fenda Labial , Fissura Palatina , Estudos de Casos e Controles , China/epidemiologia , Fenda Labial/genética , Fissura Palatina/genética , Predisposição Genética para Doença , Genótipo , Humanos , Polimorfismo de Nucleotídeo Único/genética
14.
Glob Chang Biol ; 28(16): 4923-4934, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35490304

RESUMO

Increases in terrestrial water-use efficiency (WUE) have been reported in many studies, pointing to potential changes in physiological forcing of global carbon and hydrological cycles. However, gains in WUE are of uncertain magnitude over longer (i.e. >10 years) periods of time largely owing to difficulties in accounting for structural and physiological acclimation. 13 C signatures (i.e. δ13 C) of plant organic matter have long been used to estimate WUE at temporal scales ranging from days to centuries. Mesophyll conductance is a key uncertainty in estimated WUE owing to its influence on diffusion of CO2 to sites of carboxylation. Here we apply new knowledge of mesophyll conductance to 464 δ13 C chronologies in tree-rings of 143 species spanning global biomes. Adjusted for mesophyll conductance, gains in WUE during the 20th century (0.15 ppm year-1 ) were considerably smaller than those estimated from conventional modelling (0.26 ppm year-1 ). Across the globe, mean sensitivity of WUE to atmospheric CO2 was 0.15 ppm ppm-1 . Ratios of internal-to-atmospheric CO2 (on a mole fraction basis; ci /ca ) in leaves were mostly constant over time but differed among biomes and plant taxa-highlighting the significance of both plant structure and physiology. Together with synchronized responses in stomatal and mesophyll conductance, our results suggest that ratios of chloroplastic-to-atmospheric CO2 (cc /ca ) are constrained over time. We conclude that forest WUE may have not increased as much as previously suggested and that projections of future climate forcing via CO2 fertilization may need to be adjusted accordingly.


Assuntos
Dióxido de Carbono , Água , Florestas , Fotossíntese/fisiologia , Folhas de Planta/fisiologia
15.
FASEB J ; 35(6): e21543, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34046950

RESUMO

Clinically, bone destruction caused by Mycobacterium tuberculosis was serious especially in patients with vitamin D (VD) deficiency. However, the role of VD in M. tuberculosis-induced bone destruction remains clear. In this context, we investigate the role of VD and vitamin D receptor (VDR) in the M. tuberculosis-induced bone destruction. First, we infected RAW264.7 and bone marrow-derived macrophages (BMMs) with Mycobacterium bovis Bacillus Calmette-Guérin (M. bovis BCG) in vitro. Then, we activated VDR through VD administration. TRAP and FAK staining, bone resorption assays, immunofluorescence staining, qPCR, and western blot were carried out. In vivo, the M. tuberculosis-induced osteolytic model on the murine skull was established and the µCT and histological analyses were performed. We found that VDR and TRAP were upregulated in bone tuberculosis tissue and proved that M. tuberculosis infection promoted osteoclastogenesis in RAW264.7 and BMMs. VD could inhibit osteoclasts differentiation, fusion, and bone resorption dose-dependently. However, when VDR was knocked down, the inhibitory effect of VD on osteoclasts disappeared. In mechanism, activation of VDR inhibits the phosphorylation of IκB α, thereby inhibiting NFκB signaling pathway and alleviating osteoclastogenesis. Furthermore, in the skull osteolysis model, VD administration reduced osteolysis, but not in VDR-/- mice. Our study, for the first time, demonstrates that activation of VDR by VD administration inhibits M. tuberculosis-induced bone destruction. Our results reveal that VD and VDR are potential therapeutic targets for M. tuberculosis-induced bone destruction, and are of great clinical significance for the development of new therapeutic strategies.


Assuntos
Macrófagos/efeitos dos fármacos , Mycobacterium tuberculosis/patogenicidade , NF-kappa B/antagonistas & inibidores , Osteólise/prevenção & controle , Receptores de Calcitriol/metabolismo , Tuberculose/complicações , Vitamina D/administração & dosagem , Animais , Macrófagos/metabolismo , Macrófagos/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/genética , NF-kappa B/metabolismo , Osteólise/etiologia , Osteólise/metabolismo , Osteólise/patologia , Receptores de Calcitriol/genética , Tuberculose/microbiologia , Vitaminas/administração & dosagem
16.
J Org Chem ; 87(16): 10576-10591, 2022 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-35904504

RESUMO

Transition metal-catalyzed [4 + 2 + 1] cycloaddition of in situ generated ene/yne-ene-allenes (from ene/yne-ene propargyl esters) and carbon monoxide (CO) gives the [4 + 2 + 1] cycloadducts rather than [2 + 2 + 1] cycloadducts. Investigating the mechanism of this [4 + 2 + 1] reaction and understanding why the [2 + 2 + 1] reaction does not compete and the role of the allene moiety in the substrates are important. This is also helpful to guide the future design of new [4 + 2 + 1] cycloadditions. Reported here are the kinetic and computed studies of the [4 + 2 + 1] reactions of ene-ene propargyl esters and CO. A quantum chemical study (at the DLPNO-CCSD(T)//BMK level) revealed that the [4 + 2 + 1] reaction includes four key steps, which are 1,3-acyloxy migration (rate-determining step), oxidative cyclization, CO migratory insertion, and reductive elimination. The allene moiety in the substrates is critical for providing additional coordination to the rhodium center in the final step of the catalytic cycle, which in turn favors the reductive elimination transition state in the [4 + 2 + 1] rather than in the [2 + 2 + 1] pathway. The CO insertion step in the [4 + 2 + 1] reaction, which could occur through either the UP (favored here) or DOWN CO insertion pathway, has also been deeply scrutinized, and some guidance from this analysis has been provided to help the future design of new [4 + 2 + 1] reactions. Quantum chemical calculations have also been applied to explain why [4 + 2] and [4 + 1] cycloadditions do not happen and how trienes as side products for some substrates are generated.


Assuntos
Ródio , Alcadienos , Monóxido de Carbono , Catálise , Reação de Cicloadição , Ésteres
17.
PLoS Genet ; 15(11): e1008477, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31747400

RESUMO

The kinetochore is the central molecular machine that drives chromosome segregation in all eukaryotes. Genetic studies have suggested that protein sumoylation plays a role in regulating the inner kinetochore; however, the mechanism remains elusive. Here, we show that Saccharomyces cerevisiae Ulp2, an evolutionarily conserved SUMO specific protease, contains a previously uncharacterized kinetochore-targeting motif that recruits Ulp2 to the kinetochore via the Ctf3CENP-I-Mcm16CENP-H-Mcm22CENP-K complex (CMM). Once recruited, Ulp2 selectively targets multiple subunits of the kinetochore, specifically the Constitutive Centromere-Associated Network (CCAN), via its SUMO-interacting motif (SIM). Mutations that impair the kinetochore recruitment of Ulp2 or its binding to SUMO result in an elevated rate of chromosome loss, while mutations that affect both result in a synergistic increase of chromosome loss rate, hyper-sensitivity to DNA replication stress, along with a dramatic accumulation of hyper-sumoylated CCAN. Notably, sumoylation of CCAN occurs at the kinetochore and is perturbed by DNA replication stress. These results indicate that Ulp2 utilizes its dual substrate recognition to prevent hyper-sumoylation of CCAN, ensuring accurate chromosome segregation during cell division.


Assuntos
Centrômero/genética , Segregação de Cromossomos/genética , Endopeptidases/genética , Proteínas de Saccharomyces cerevisiae/genética , Sumoilação/genética , Proteínas de Ciclo Celular/genética , Proteínas Cromossômicas não Histona/genética , Replicação do DNA/genética , Proteínas de Ligação a DNA/genética , Cinetocoros/metabolismo , Saccharomyces cerevisiae/genética
18.
J Obstet Gynaecol Res ; 48(3): 796-805, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35016264

RESUMO

AIM: Ovarian cancer is a main contributor of cancer-relevant deaths among women worldwide due to high incidence and mortality. Mounting evidence has unveiled that lncRNAs play critical roles in malignancies, including ovarian cancer. Although the tumor suppressor function of HCG11 in prostate cancer and glioma has been proved, investigations on HCG11 role in ovarian cancer are still scarce. METHODS: Gene or protein expression was quantified by RT-qPCR or western blot. HCG11 effects on ovarian cancer were assessed by functional assays. Bioinformatics analysis and mechanism experiments were implemented to identify the association among HCG11, miR-1270, and PTEN. RESULTS: HCG11 was weakly expressed in ovarian cancer and functioned as a tumor suppressor in ovarian cancer by retarding cell proliferation, migration, and EMT. Besides, HCG11 could bind to miR-1270 and PTEN was a target gene of miR-1270. Mechanically, HCG11 competitively bound with miR-1270 to upregulate PTEN. From rescue experiments, HCG11 impeded AKT/mTOR pathway to retard ovarian cancer cell growth by miR-1270/PTEN. CONCLUSIONS: HCG11 was a tumor suppressor in ovarian cancer cells and additionally, HCG11 regulated AKT/mTOR pathway to hinder ovarian cancer cell growth via modulating miR-1270/PTEN, indicating that HCG11 may represent a promising target for effective treatment of ovarian cancer patients.


Assuntos
MicroRNAs , Neoplasias Ovarianas , PTEN Fosfo-Hidrolase , RNA Longo não Codificante , Transdução de Sinais , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Feminino , Humanos , MicroRNAs/metabolismo , Neoplasias Ovarianas/genética , PTEN Fosfo-Hidrolase/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Longo não Codificante/genética , Transdução de Sinais/genética
19.
Cleft Palate Craniofac J ; 59(4): 436-441, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34018417

RESUMO

OBJECTIVE: To verify the advantages and indications of 1-stage and 2-stage repair for asymmetric bilateral cleft lip (BCL). DESIGN: Retrospective study. SETTING: From January 2004 to December 2016 in our department. PATIENTS: Patients with BCL. MAIN OUTCOME MEASURE(S): Over 6 months after the operation, the surgery outcomes were evaluated and graded by 2 experienced surgeons. RESULTS: The result of surgery was evaluated using the scoring method of Mortier et al and Anastassov and Chipkov. Among 133 patients with asymmetric BCL, 61 (45.9%) had 1-stage repair and 72 (54.1%) had 2-stage repair. Sixty-eight (51.1%) patients had complete-incomplete cleft lip (CL), and those who underwent 1-stage repair showed a trend of better outcome (P = .028). Fifty (37.6%) patients with incomplete-microform CL showed no significant difference between the outcomes of 2 surgery plans (P = .253). In 15 (11.3%) patients with complete-microform CL, only one had 1-stage repair with a score of 8.5. The other 14 patients with 2-stage repair were scored 3.68 ± 1.28. Two-stage repair was preferable when the deformity degree was very different on 2 sides, as it could reduce unnecessary scar tissue and extend the nasal columella. One-stage repair could help to achieve the anatomical reduction of the orbicularis oris and a better contour of the vermilion tubercle. CONCLUSION: One-stage repair is recommended for patients with complete-incomplete CL and incomplete-microform CL. Two-stage repair for patients with complete-microform CL is preferred in our center, but more studies are required to support this conclusion.


Assuntos
Fenda Labial , Procedimentos de Cirurgia Plástica , Fenda Labial/cirurgia , Humanos , Lábio/cirurgia , Septo Nasal/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Estudos Retrospectivos
20.
New Phytol ; 229(3): 1326-1338, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32984961

RESUMO

Carbon isotope discrimination (Δ) has been used widely to infer intrinsic water-use efficiency (iWUE) of C3 plants, a key parameter linking carbon and water fluxes. Despite the essential role of mesophyll conductance (gm ) in photosynthesis and Δ, its effect on Δ-based predictions of iWUE has generally been neglected. Here, we derive a mathematical expression of iWUE as a function of Δ that includes gm (iWUEmes ) and exploits the gm -stomatal conductance (gsc ) relationship across drought-stress levels and plant functional groups (deciduous or semideciduous woody, evergreen woody and herbaceous species) in a global database. iWUEmes was further validated with an independent dataset of online-Δ and CO2 and H2 O gas exchange measurements with seven species. Drought stress reduced gsc and gm by nearly one-half across all plant functional groups, but had no significant effect on the gsc  : gm ratio, with a well supported value of 0.79 ± 0.07 (95% CI, n = 198). gm was negatively correlated to iWUE. Incorporating the gsc  : gm ratio greatly improved estimates of iWUE, compared with calculations that assumed infinite gm . The inclusion of the gsc  : gm ratio, fixed at 0.79 when gm was unknown, proved desirable to eliminate significant errors in estimating iWUE from Δ across various C3 vegetation types.


Assuntos
Células do Mesofilo , Água , Dióxido de Carbono , Fotossíntese , Folhas de Planta , Estômatos de Plantas
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