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1.
J Clin Invest ; 131(6)2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33720048

RESUMO

Chronic HIV-1 infection is generally characterized by progressive CD4+ T cell depletion due to direct and bystander death that is closely associated with persistent HIV-1 replication and an inflammatory environment in vivo. The mechanisms underlying the loss of CD4+ T cells in patients with chronic HIV-1 infection are incompletely understood. In this study, we simultaneously monitored caspase-1 and caspase-3 activation in circulating CD4+ T cells, which revealed that pyroptotic and apoptotic CD4+ T cells are distinct cell populations with different phenotypic characteristics. Levels of pyroptosis and apoptosis in CD4+ T cells were significantly elevated during chronic HIV-1 infection, and decreased following effective antiretroviral therapy. Notably, the occurrence of pyroptosis was further confirmed by elevated gasdermin D activation in lymph nodes of HIV-1-infected individuals. Mechanistically, caspase-1 activation closely correlated with the inflammatory marker expression and was shown to occur through NLRP3 inflammasome activation driven by virus-dependent and/or -independent ROS production, while caspase-3 activation in CD4+ T cells was more closely related to T cell activation status. Hence, our findings show that NLRP3-dependent pyroptosis plays an essential role in CD4+ T cell loss in HIV-1-infected patients and implicate pyroptosis signaling as a target for anti-HIV-1 treatment.

2.
Drug Deliv ; 28(1): 510-519, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33657950

RESUMO

Intra-tumor heterogeneity is widely accepted as one of the key factors, which hinders cancer patients from achieving full recovery. Especially, cancer stem cells (CSCs) may exhibit self-renewal capacity, which makes it harder for complete elimination of tumor. Therefore, simultaneously inhibiting CSCs and non-CSCs in tumors becomes a promising strategy to obtain sustainable anticancer efficacy. Salinomycin (Sal) was reported to be critical to inhibit CSCs. However, the poor bioavailability and catastrophic side effects brought about limitations to clinical practice. To solve this problem, we previously constructed gelatinase-stimuli nanoparticles composed of nontoxic, biocompatible polyethylene glycol-polycaprolactone (PEG-PCL) copolymer with a gelatinase-cleavable peptide Pro-Val-Gly-Leu-Iso-Gly (PVGLIG) inserted between the two blocks of the copolymer. By applying our "smart" gelatinase-responsive nanoparticles for Sal delivery, we have demonstrated specific accumulation in tumor, anti-CSCs ability and reduced toxicity of Sal-NPs in our previous study. In the present study, we synthesized Sal-Docetaxel-loaded gelatinase-stimuli nanoparticles (Sal-Doc NP) and confirmed single emulsion as the optimal method of producing Sal-Doc NPs (Sal-Doc SE-NP) in comparison with nanoprecipitation. Sal-Doc SE-NPs inhibited both CSCs and non-CSCs in mice transplanted with cervical cancer, and might be associated with enhanced restriction of epithelial-mesenchymal transition (EMT) pathway. Besides, the tumorigenic capacity and growing speed were obviously suppressed in Sal-Doc-SE-NPs-treated group in rechallenge experiment. Our results suggest that Sal-Doc-loaded gelatinase-stimuli nanoparticles could be a promising strategy to enhance antitumor efficacy and reduce side effects by simultaneously suppressing CSCs and non-CSCs.

3.
Int J Pharm ; 597: 120343, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33545288

RESUMO

Armodafinil is typically used in clinical practice to maintain cognition and wakefulness in patients suffering from sleep deprivation. However, its poor water solubility and large dosage limit its effective application. Herein, we formulated armodafinil in a nanocrystal hydrogel (NCsG) with appropriate fluidity and viscosity, capable of rapidly dissolving after staying in the nasal cavity for > 4 h and then penetrating the mucosa as quickly as possible in vitro. We found that armodafinil NCsG was biologically safe, as it had no visible ciliary toxicity, as well as extremely stable due to the existence of intermolecular hydrogen-bonding forces. Nasal administration of armodafinil NCsG proved to be more efficient and targeted than oral administration due to its preferential absorption in plasma and more-concentrated distribution in the brain. In addition, compared with the model group, sleep-deprived rats treated with NCsG undergoing Morris water maze (MWM) behavioral experiments had shorter escape latency and much more shuttle times across the platform. Meanwhile, in the open-field test (OFT), these same rats had longer periods of movement in the center, longer time spent upright, and lower anxiety, which clearly demonstrated improved cognitive awareness and wakefulness after intranasal administration. Moreover, we speculated that armodafinil NCsG had a protective effect on hippocampal neurons in Cortical Area 1 (CA1), which is closely related to cognitive function, by upregulating brain-derived neurotrophic factor (BDNF) protein expression. Consequently, the intranasal administration of armodafinil NCsG could serve as a promising integrated-control measure for sleep deprivation.

4.
Emerg Microbes Infect ; 10(1): 416-423, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33620297

RESUMO

Morbidity and mortality of non-AIDS-defining diseases (NADs) have become the increasing burden of people living with HIV (PLWH) with long-term antiretroviral therapy (ART). We aimed to quantify the contribution of modifiable risk factors to NADs. We included PLWHs starting ART at the Third People's Hospital of Shenzhen (China) from Jan 1, 2010 to Dec 31, 2017. We defined NAD outcomes of interest as cardiovascular disease (CVD), end-stage liver disease (ESLD), advanced renal disease (ARD), and non-AIDS-defining cancers (NADCs). We estimated incidence of outcomes and population-attributable fractions (PAFs) of modifiable traditional and HIV-related risk factors for each outcome. Overall, 8,301 participants (median age at study entry, 31 years) contributed 33,146 person-years of follow-up (PYFU). Incidence of CVD (362/100,000 PYFU) was the highest among outcomes, followed by that of ARD (270/100,000 PYFU), ESLD (213/100,000 PYFU), and NADC (152/100,000 PYFU). Totally, 34.14% of CVD was attributable to smoking, 7.98% to hypertension, and 6.44% to diabetes. For ESLD, 24.57% and 25.04% of it could be avoided if chronic hepatitis B and C virus infection, respectively, did not present. The leading PAFs for ARD were declined estimated glomerular filtration rate (eGFR) (39.68%) and low CD4 count (39.61%), followed by diabetes (10.19%). PAFs of hypertension, diabetes, and smoking for CVD, and declined eGFR and diabetes for ARD increased with age. The contribution of traditional risk factors for these NADs far outweighed the HIV-related risk factors. Individual-level interventions and population-level policy-making is needed to focus on these factors to prevent NADs in long-term management of HIV infection.

5.
Appl Environ Microbiol ; 87(6)2021 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-33397697

RESUMO

Conjugated linoleic acids (CLAs) have attracted more attention as functional lipids due to their potential physiological activities, including anticancer, anti-inflammatory, anti-cardiovascular disease, and antidiabetes activities. Microbiological synthesis of CLA has become a compelling method due to its high isomer selectivity and convenient separation and purification processes. In Lactobacillus plantarum, the generation of CLA from linoleic acids (LAs) requires the combination of CLA oleate hydratase (CLA-HY), CLA short-chain dehydrogenase (CLA-DH), and CLA acetoacetate decarboxylase (CLA-DC), which are separately encoded by cla-hy, cla-dh, and cla-dc. However, the regulatory mechanisms of CLA synthesis remain unknown. In this study, we found that a LysR family transcriptional regulator, LTTR, directly bound to the promoter region of the cla operon and activated the transcription of cla-dh and cla-dc. The binding motif was also predicted by bioinformatics analysis and verified by electrophoretic mobility shift assays (EMSAs) and DNase I footprinting assays. The lttR overexpression strain showed a 5-fold increase in CLA production. Moreover, we uncovered that the transcription of lttR is activated by LA. These results indicate that LttR senses LA and promotes CLA production by activating the transcription of cla-dh and cla-dc. This study reveals a new regulatory mechanism in CLA biotransformation and provides a new potential metabolic engineering strategy to increase the yield of CLA.IMPORTANCE Our work has identified a novel transcriptional regulator, LTTR, that regulates the production of CLA by activating the transcription of cla-dh and cla-dc, essential genes participating in CLA synthesis in Lactobacillus plantarum This study provides insight into the regulatory mechanism of CLA synthesis and broadens our understanding of the synthesis and regulatory mechanisms of the biosynthesis of CLA.


Assuntos
Proteínas de Bactérias/genética , Lactobacillus plantarum/genética , Lactobacillus plantarum/metabolismo , Ácidos Linoleicos Conjugados/biossíntese , Fatores de Transcrição/genética , Sítios de Ligação , Óperon
6.
Nat Commun ; 12(1): 550, 2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-33483503

RESUMO

Understanding and manipulating hot electron dynamics in semiconductors may enable disruptive energy conversion schemes. Hot electrons in bulk semiconductors usually relax via electron-phonon scattering on a sub-picosecond timescale. Quantum-confined semiconductors such as quantum dots offer a unique platform to prolong hot electron lifetime through their size-tunable electronic structures. Here, we study hot electron relaxation in electron-doped (n-doped) colloidal CdSe quantum dots. For lightly-doped dots we observe a slow 1Pe hot electron relaxation (~10 picosecond) resulting from a Pauli spin blockade of the preoccupying 1Se electron. For heavily-doped dots, a large number of electrons residing in the surface states introduce picosecond Auger recombination which annihilates the valance band hole, allowing us to observe 300-picosecond-long hot electrons as a manifestation of a phonon bottleneck effect. This brings the hot electron energy loss rate to a level of sub-meV per picosecond from a usual level of 1 eV per picosecond. These results offer exciting opportunities of hot electron harvesting by exploiting carrier-carrier, carrier-phonon and spin-spin interactions in doped quantum dots.

7.
Food Funct ; 12(3): 1079-1086, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33367350

RESUMO

It has been reported that Lactobacillus can remove cholesterol and thus might play an important role in lowering cholesterol in humans, but the underlying mechanism is still controversial. To confirm whether different strains have different cholesterol-lowering mechanisms, we explored the cholesterol-lowering abilities of different Lactobacillus plantarum strains, and the factors influencing their abilities. We found that all nine strains reduced the cholesterol concentration to some extent, but there were significant differences among them. In MRS broth, L. plantarum AR113 and AR171 showed the greatest cholesterol-lowering abilities of 27.89% and 19.90%, respectively, but AR501 and AR300 only showed reductions of 0.34% and 0.91%, respectively. Upon addition of 0.1% ox bile, the cholesterol-removal capability of most strains increased. L. plantarum AR511 showed the highest cholesterol removal rate, which increased from 5.8% to 37.14%, i.e., by a factor of approximately 6.4, but there was no significant change in the cholesterol removal rate of AR171. These results suggested that the effect of ox bile on the cholesterol-lowering ability was strain-specific. Except for the strains AR171, AR237 and AR495, the cholesterol-removal ability of the remaining six strains was positively correlated with the amount of free bile acid released. The addition of a bile salt hydrolase inhibitor had some effect on the cholesterol-removal ability of the six strains of bacteria other than AR171, AR237 and AR495, but little influence on the latter three. The effect of BSH was strain-specific. Similarly, the effect of pH was also strain-specific. Taken together, these results suggest that different strains of L. plantarum have different cholesterol-lowering capacities and different influencing factors. Therefore, further research is needed to explore the exact mechanism by which different strains lower cholesterol.

8.
J Dairy Sci ; 104(3): 2520-2528, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33358811

RESUMO

α-Lactalbumin (α-LA) and ß-lactoglobulin (ß-LG) were isolated from yak milk and identified by mass spectrometry. The variant of α-LA (L8IIC8) in yak milk had 123 amino acids, and the sequence differed from α-LA from bovine milk. The amino acid at site 71 was Asn (N) in domestic yak milk, but Asp (D) in bovine and wild yak milk sequences. Yak ß-LG had 2 variants, ß-LG A (P02754) and ß-LG E (L8J1Z0). Both domestic yak and wild yak milk contained ß-LG E, but it was absent in bovine milk. The amino acid at site 158 of ß-Lg E was Gly (G) in yak but Glu (E) in bovine. The yak α-LA and ß-LG secondary structures were slightly different from those in bovine milk. The denaturation temperatures of yak α-LA and ß-LG were 52.1°C and 80.9°C, respectively. This study provides insights relevant to food functionality, food safety control, and the biological properties of yak milk products.

9.
J Phys Chem Lett ; : 86-93, 2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33306386

RESUMO

Solution-processed quantum-confined nanocrystals are important building blocks for scalable implementation of quantum information science. Extensive studies on colloidal quantum dots (QDs) have revealed subpicosecond hole spin relaxation, whereas the electron spin dynamics remains difficult to probe. Here we study electron and hole spin dynamics in CdSe colloidal nanoplatelets (also called quantum wells) of varying thicknesses using circularly polarized transient absorption spectroscopy at room temperature. The clear spectroscopic features of transition bands associated with heavy, light, and spin-orbit split-off holes enabled separate probes of electron and hole dynamics. The hole spin-flip occurred within ∼200 fs, arising from strong spin-orbit coupling in the valence band. The electron spin lifetime decreased from 6.2 to 2.2 ps as the platelet thickness is reduced from 6 to 4 monolayers, reflecting an exchange interaction between the electron and the hole and/or surface dangling bond spins enhanced by quantum confinement.

10.
J Agric Food Chem ; 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33227196

RESUMO

Fragrant Brassica species seed oils (FBO) produced in China are mainly obtained from rapeseed (Brassica napus: B. napus) and mustard seeds (Brassica juncea: B. juncea). The characterization and differences of aroma profiles between those two species remain unclear. In this study, the volatile compounds in FBOs were systemically extracted by headspace solid-phase microextraction and solvent-assisted flavor evaporation combined with ultrasound and identified by comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry (GC×GC-TOFMS) and gas chromatography-olfactometry (GC-O). Ninety-three odorants were identified as aroma-active compounds with flavor dilution (FD) factors ranging from 1 to 6561. Moreover, 63 key compounds exhibited their odor activity values (OAVs) to be greater than 1. The oils of the two species were successfully recombinated with their key odorants. B. juncea oils presented stronger pungent-like, pickled-like, and fishy like notes compared to B. napus oils. The key odor differences were primarily attributed to the concentration of 3-butenenitrile, 4-(methylsulfanyl)butanenitrile, 5-(methylsulfanyl)pentanenitrile, 3-isothiocyanato-1-propene, 3-methyl-3-butenenitrile, isothiocyanatocyclopropane, (methylsulfanyl)acetonitrile, dimethyl sulfide, dimethyl trisulfide, and 3-(methyldisulfanyl)-1-propene. This work provides a guide for the selection of raw materials and odor markers in fragrant B. napus and B. juncea oils.

11.
J Thorac Oncol ; 2020 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-33166719

RESUMO

INTRODUCTION: Treatment options in second-line extensive-stage small-cell lung cancer (ED-SCLC) setting are limited. PASSION (ClinicalTrials.gov identifier: NCT03417895) was a phase 2 study of camrelizumab plus apatinib in ED-SCLC after platinum-based chemotherapy. METHODS: In Stage 1, patients were randomized (1:1:1) to receive camrelizumab 200 mg every 2 weeks plus apatinib 375 mg once daily (QD), 5 days on/2 days off, or 7 days on/7 days off (six patients each cohort). Based on the tolerability during the first 28-day cycle and efficacy data in Stage 1, one cohort was chosen to expand to 45 patients in Stage 2. The primary endpoint was objective response rate (ORR). RESULTS: From Apr 20, 2018 to Mar 12, 2019, 59 patients were enrolled, with 47 patients in the QD cohort. In the QD cohort, confirmed ORR reached 34.0% (95% CI 20.9‒49.3), the median progression-free survival (PFS) was 3.6 months, and the median overall survival (OS) was 8.4 months. Chemotherapy-sensitive and chemotherapy-resistant patients (defined as patients with disease relapsed ≥90 and ˂90 days after platinum-based chemotherapy, respectively) had comparable confirmed ORR (37.5% versus 32.3%), median PFS (3.6 versus 2.7 months), and median OS (9.6 versus 8.0 months). Treatment-related adverse events (TRAEs) of grade ≥3 were reported in 43 (72.9%) of 59 patients. Five (8.5%) patients discontinued due to TRAEs. CONCLUSION: Camrelizumab plus apatinib showed potential antitumor activity in both chemotherapy-sensitive and chemotherapy-resistant ED-SCLC patients who had failed platinum-based chemotherapy with acceptable toxicity profile. This phase 2 data warrant further clinical studies of camrelizumab plus apatinib in SCLC.

12.
Emerg Microbes Infect ; 9(1): 2550-2561, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33131455

RESUMO

Using normalization of CD4 counts as the main evaluation parameter of complete immune restoration for HIV-1 patients under antiretroviral therapy (ART) might be not enough. A comprehensive evaluation system more accurately reflecting immune restoration are urgently needed. Totally, 91,805 HIV-1 patients from 17 tertiary hospitals in China during 2005-2018 were included in this study. Immune restoration and mortality were assessed. Patients initiated ART with baseline CD4 counts <50, 50-199, 200-349, 350-499, and ≥500 cells/µL, and results showed an increase in the median CD4 counts to 445 (12-year), 467 (12-year), 581 (11-year), 644 (7-year), and 768 cells/µL (5-year), as well as the CD4/CD8 ratio to 0.59 (12-year), 0.65 (12-year), 0.79 (11-year), 0.82 (7-year), 0.9 (5-year), respectively. The median CD8 count was relatively high (median range 732-845 cells/µL), regardless of the baseline CD4 counts. Furthermore, the probabilities of death in patients achieving CD4 counts ≥500 cells/µL and CD4/CD8 ratio ≥0.8 simultaneously were significantly lower than those in patients achieving either CD4 counts ≥500 cells/µL (2.77% vs 3.50%, p=0.02) or CD4/CD8 ≥ 0.8 (2.77% vs 4.28%, p<0.001) after 12-year of ART. In this study, a new binary-indicator would accurately assess immune restoration in the era of "treat all."

13.
Small ; 16(49): e2005272, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33205608

RESUMO

The potassium ion batteries (KIBs) based on conversion/alloying reaction mechanisms show high theoretical capacity. However, their applications are hampered by the poor cyclability resulting from the inherent large volume variations and the sluggish kinetics during K+ repeated insertion/extraction process. Herein, taken Sb2 Se3 as a model material, by rational design, nickel doped-carbon coated Sb2 Se3 nanorods (denoted as (Sb0.99 Ni0.01 )2 Se3 @C) are prepared through combined strategies of the conductive encapsulation and crystal structure modification. The carbon coating acts as an efficient buffer layer that maintains superior structural stability upon cycling. The introduction of Ni atoms can enhance electrical conductivity, leading to outstanding rate performance, which are confirmed by density functional theory calculation. The (Sb0.99 Ni0.01 )2 Se3 @C displays excellent reversible capacity (410 mAh g-1 at 0.1 A g-1 after 100 cycles) and unprecedented rate capability (140 mAh g-1 at 10 A g-1 ). Furthermore, KFeHCF//(Sb0.99 Ni0.01 )2 Se3 @C full cell exhibits a high specific capacity (408 mAh g-1 at 0.1 A g-1 ), superior rate capability (260 mAh g-1 at 2 A g-1 ). This work can open up a new avenue for the design of stable conversion/alloying-based anodes for high energy density KIBs.

14.
Biomed Pharmacother ; 131: 110684, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33152903

RESUMO

Marein, an active component of the Coreopsis tinctoria Nutt. plant, is known to improve diabetic nephropathy (DN). However, its anti-diabetic functions in DN and potential mechanisms remain unclear. The aim of this study was to elucidate the effects and mechanisms of Marein in diabetic db/db mice with DN, and in high glucose-treated HK-2 cells. In vivo, treating diabetic db/db mice with Marein for 12 consecutive weeks restored diabetes-induced hyperglycemia and dyslipidemia, and ameliorated renal function deterioration, glomerulosclerosis, and renal ectopic lipid deposition. Marein exerted renoprotective effects by directly inhibiting renal tubule sodium glucose transporter 2 (SGLT2) expression, and then activating the AMP-activated protein kinase (AMPK)/acetyl CoA carboxylase (ACC)/peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) pathway in db/db mice. Meanwhile, Marein ameliorated fibrosis and inflammation by suppressing the pro-inflammatory factors interleukin-6 (IL-6) and monocyte chemotactic protein-1 (MCP-1), and expression of the extracellular matrix proteins, fibronectin (FN) and collagen 1 (COL1) in diabetic mice. In vitro, MDCK monolayer cells were established to explore the characteristics of Marein transmembrane transport. Marein was found to be absorbed across the membrane at a medium level that involved active transport and this was mediated by SGLTs. In HK-2 cells, Marein decreased uptake of the fluorescent glucose analog, 2-NBDG, by 22 % by inhibiting SGLT2 expression. In high glucose-treated HK-2 cells, Marein decreased SGLT2 expression and increased phosphorylated (p)-AMPK/p-ACC to improve high glucose-induced cellular dysfunction. Furthermore, Marein treatment decreased SGLT2 expression in SGLT2-overexpressing HK-2 cells. In addition, molecular docking and dynamics analysis revealed that SGLT2 was a direct target of Marein. Collectively, our results demonstrated that Marein ameliorates DN by inhibiting renal SGLT2 and activating p-AMPK, suggesting Marein can potentially prevent DN by suppressing renal SGLT2 expression directly.

15.
Front Oncol ; 10: 1568, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33042801

RESUMO

Objective: This study investigated survival in selected Chinese patients with advanced lung adenocarcinoma who received initial chemotherapy with pemetrexed. We also explored the relationship between genetic biomarkers and pemetrexed efficacy. Methods: We retrospectively collected patients (n = 1,047) enrolled in the Chinese Patient Assistance Program from multiple centers who received pemetrexed alone or combined with platinum as initial chemotherapy and continued pemetrexed maintenance therapy for advanced lung adenocarcinoma from November 2014 to June 2017. The outcomes were duration of treatment (DOT) and overall survival (OS). Clinical features were analyzed for their influence on the treatment effect and prognosis. Next-generation sequencing (NGS) was performed to identify genetic biomarkers associated with the efficacy of pemetrexed. Results: The median DOT was 9.1 months (95% CI: 8.5-9.8), and the median OS was 26.2 months (95% CI: 24.2-28.1). OS was positively correlated with DOT (r = 0.403, P < 0.001). Multivariable analysis showed that smoking status and Eastern Cooperative Oncology Group (ECOG) performance status (PS) were independently associated with DOT; smoking status, ECOG PS, targeted therapy, and EGFR/ALK/ROS1 status were independently associated with OS. NGS in 22 patients with available samples showed genes with high mutation rates were: TP53 (54.5%), EGFR (50.0%), MYC (18.2%), and PIK3CA (13.6%). When grouped based on progression-free survival (PFS) reported in the PARAMOUNT study, the DOT > 6.9 months set was associated with PIK3CA, ALK, BRINP3, CDKN2A, CSMD3, EPHA3, KRAS, and RB1 mutations, while ERBB2 mutation was observed only in the DOT ≤ 6.9 months set. Conclusion: This study shows that initial chemotherapy with pemetrexed is an effective regimen for advanced lung adenocarcinoma in selected Chinese patients. There is no specific genetic profile predicting the benefit of pemetrexed found by NGS. Biomarkers predicting the efficacy of pemetrexed need further exploration.

16.
ACS Omega ; 5(41): 26732-26737, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33110999

RESUMO

An analytical model is developed to describe the shape of heavy droplets on solid surfaces with arbitrary wetting properties (corresponding to the contact angles ranging from 0 to 180°). This model, based on a surface of revolution by rotating two elliptic arcs, reduces to the ellipsoid model for a hydrophilic case. Experimental measurements are also conducted to verify the model. It shows that the mean curvature distribution of the developed model agrees well with that of real droplets on hydrophobic surfaces, even on superhydrophobic surfaces. For water droplets with a volume up to 1000 µL on superhydrophobic surfaces having a 162° contact angle, the errors of the predicted heights, maximum radius, and wetting radius using this model are less than 1.7%, which suggests the capability of this model in studying the wettability of heavy droplets. This model provides an accurate theoretical basis for designing and controlling the spread, transport, condensation, and evaporation of heavy droplets on superhydrophobic surfaces.

17.
Nanoscale Res Lett ; 15(1): 203, 2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33112999

RESUMO

Fast diffusion induced by thermal fluctuation and vibration has been detected at nanoscales. In this paper, the movement of particle on a graphene layer with travelling surface wave is studied by molecular dynamics simulation and theoretical model. It is proved that the particle will keep moving at the wave speed with certain prerequisite conditions, namely speed-locking effect. By expressing van der Waals (vdW) potential between particle and wavy surface as a function of curvatures, the mechanism is clarified based on the puddle of potential in a relative wave-frame coordinate. Two prerequisite conditions are proposed: the initial position of particle should locate in the potential puddle, and the initial kinetic energy cannot drive particle to jump out of the potential puddle. The parametric analysis indicates that the speed-locking region will be affected by wavelength, amplitude and pair potential between particle and wave. With smaller wavelength, larger amplitude and stronger vdW potential, the speed-locking region is larger. This work reveals a new kind of coherent movement for particles on layered material based on the puddle potential theory, which can be an explanation for fast diffusion phenomena at nano scales.

18.
Cell ; 183(3): 684-701.e14, 2020 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-33058756

RESUMO

Positive selection in Europeans at the 2q21.3 locus harboring the lactase gene has been attributed to selection for the ability of adults to digest milk to survive famine in ancient times. However, the 2q21.3 locus is also associated with obesity and type 2 diabetes in humans, raising the possibility that additional genetic elements in the locus may have contributed to evolutionary adaptation to famine by promoting energy storage, but which now confer susceptibility to metabolic diseases. We show here that the miR-128-1 microRNA, located at the center of the positively selected locus, represents a crucial metabolic regulator in mammals. Antisense targeting and genetic ablation of miR-128-1 in mouse metabolic disease models result in increased energy expenditure and amelioration of high-fat-diet-induced obesity and markedly improved glucose tolerance. A thrifty phenotype connected to miR-128-1-dependent energy storage may link ancient adaptation to famine and modern metabolic maladaptation associated with nutritional overabundance.

19.
Int J Biol Macromol ; 163: 1821-1827, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32910966

RESUMO

Chinese steamed bread (CSB) is one of the traditional staple foods of Chinese people, and its quality is mainly affected by wheat gluten and starch. Herein, four different ratios of wheat gluten and starch were selected to investigate its effects on the properties of CSB. It was observed that the surface of CSB gradually became darker, yellower, and shrank with increasing gluten-starch ratio. The hardness and chewiness of CSB decreased with the increasing of gluten-starch ratio, as well as the network structure of CSB was dense and porous. The increase of gluten content could effectively control the migration of water in the CSB. Moreover, with increasing gluten-starch ratio, the crystallinity of starch was reduced from 9.95% to 2.03%. As a result, the ratio of gluten-starch mainly affected the development of gluten network structure and starch gelatinization through the competition of water between gluten and starch in the system, which in turn affected the quality of CSB. Thus, it will provide the basis for the adaptability of wheat flour from different origins as the raw material of CSB processing, and also provide guidance for consumers to select flour with different gluten protein content to prepare steamed bread according to their preferences.

20.
ACS Appl Mater Interfaces ; 12(40): 45453-45459, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-32929951

RESUMO

Two-dimensional (2D) transition metal dichalcogenide membranes have entered the spotlight for nanofiltration application owing to the novel mass transport properties in nanochannels. However, further improving the water permeability with high molecular separation rate simultaneously is challenging. In this work, to achieve ultrafast molecule separation, MoS2 and WS2 nanosheets with ultrasmall lateral size (<100 nm) are fabricated by sucrose-assisted mechanochemical exfoliation. Ultrasmall nanosheets in the membranes cut down average length of water-transporting paths and create more nanochannels and nanocapillaries for water molecules to pass through membranes. The water flux of these kinds of MoS2 and WS2 membranes are significantly enhanced to 918 and 828 L/m2 h bar, respectively, which is four and two times higher than those of previously reported MoS2 and WS2 membranes with larger lateral size nanosheets. In addition, MoS2 and WS2 membranes display excellent rejection performance for rhodamine B and Evans blue with a high rejection rate (∼99%). This study provides a promising method to improve the performance of 2D laminar membranes for nanofiltration application by using ultrasmall 2D nanosheets.

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