China has reached the lewis turning point

In the past several years, labor shortages in China have become an issue. However, there is heated debate as to whether China has passed the Lewis turning point and moved from a period of unlimited supply to a new era of labor shortage. Most empirical studies on this topic focus on estimation of total labor supply and demand. Yet the poor quality of China’s labor statistics leaves the debate open. In this paper, China’s position along the Lewis continuum is examined though primary surveys of wage rates, which offer a more reliable statistic than employment data. Our results show a clear rising trend in real wage rates since 2003. The acceleration of real wages even in slack seasons indicates that the era of surplus labor is over. This finding has important policy implications for China’s future development.dual economy, employment data, Labor market, Lewis model, Supply and demand, surplus labor, wage rates,

Modified Si–Jun–Zi–Tang Attenuates Airway Inflammation in a Murine Model of Chronic Asthma by Inhibiting Teff Cells via the mTORC1 Pathway

Background: Modified Si–Jun–Zi–Tang (MSJZT), a multi-herb formulation, is frequently used in traditional Chinese medicine for patients during the remission stage of asthma. However, the pharmacological basis underlying the effects of MSJZT on asthma has yet to be elucidated. This study aims at evaluating the anti-asthmatic effects of MSJZT and investigating its possible mechanism.Methods: A chronic murine model of asthma was established by sensitization and repeated challenge with ovalbumin (OVA) in female BALB/c mice, followed with oral administration of MSJZT during remission, and then mouse were re-challenged by OVA. The chemical profile of MSJZT was analyzed by high-performance liquid chromatography. The characteristic features of allergic asthma, including airway hyperreactivity, histopathology, cytokine levels (IL-4, -5, -13, -17, and INF-γ), T regulatory (Treg) lymphocytes (Foxp3+CD4+CD25+), and T effector (Teff) lymphocytes (Foxp3-CD25+CD4+) in bronchoalveolar lavage fluid (BALF), and downstream proteins of mTORC1/2 signaling pathway were examined.Results: MSJZT markedly suppressed airway hyper-responsiveness to aerosolized methacholine, and reduced levels of IL-4, IL-5, and IL-13 in the BALF. Histological studies showed that MSJZT significantly reduced inflammatory infiltration in lung tissues. The percentage and absolute number of Teff cells were suppressed to a remarkable level by MSJZT without affecting Treg cells. Furthermore, MSJZT effectively inhibited the mTORC1 activity, but exerted limited effects on mTORC2, as assessed by the phosphorylation of the mTORC1 and mTORC2 substrates, S6 ribosomal protein, p70 S6 kinase, mTOR S2481, and Akt, respectively.Conclusion: MSJZT attenuated chronic airway inflammation in a mouse model of asthma by inhibiting Teff cells, which occurred, at least in part, via modulation of the mTORC1 signaling pathway

Astragaloside IV Ameliorates Airway Inflammation in an Established Murine Model of Asthma by Inhibiting the mTORC1 Signaling Pathway

Astragaloside IV (AS-IV), a main active constituent of Astragalus membranaceus, has been confirmed to have antiasthmatic effects. However, it remained unclear whether the beneficial effects of AS-IV on asthma were attributed to the mTOR inhibition; this issue was the focus of the present work. BALB/c mice were sensitized and challenged with ovalbumin followed with 3 weeks of rest/recovery and then reexposure to ovalbumin. AS-IV was administrated during the time of rest and reexposure. The characteristic features of allergic asthma, including airway hyperreactivity, histopathology, cytokines (IL-4, IL-5, IL-13, IL-17, and INF-γ), and CD4+CD25+Foxp3+Treg cells in bronchoalveolar lavage fluid (BALF), and downstream proteins of mTORC1/2 signaling were examined. AS-IV markedly suppressed airway hyperresponsiveness and reduced IL-4, IL-5, and IL-17 levels and increased INF-γ levels in the BALF. Histological studies showed that AS-IV markedly decreased inflammatory infiltration in the lung tissues. Notably, AS-IV inhibited mTORC1 activity, whereas it had limited effects on mTORC2, as assessed by phosphorylation of mTORC1 and mTORC2 substrates S6 ribosomal protein, p70 S6 Kinase, and Akt, respectively. CD4+CD25+Foxp3+Treg cells in BALF were not significantly changed by AS-IV. Together, these results suggest that the antiasthmatic effects of AS-IV were at least partially from inhibiting the mTORC1 signaling pathway

Concentration- and time-dependent response of human gingival fibroblasts to fibroblast growth factor 2 immobilized on titanium dental implants

Qianli Ma1*, Wei Wang1*, Paul K Chu2, Shenglin Mei1,2, Kun Ji3, Lei Jin4, Yumei Zhang11Department of Prosthetic Dentistry, School of Stomatology, Fourth Military Medical University, Xi'an, People's Republic of China; 2Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong, People's Republic of China; 3Department of Pediatric Dentistry, School of Stomatology, Fourth Military Medical University, Xi'an, People's Republic of China; 4Stomatology Department, Jinling Hospital, School of Medicine, Southern Medical University, Nanjing, People's Republic of China*These authors contributed equally to this workBackground: Titanium (Ti) implants are widely used clinically, but peri-implantitis remains one of the most common and serious complications. Healthy integration between gingival tissue and the implant surface is critical to long-term success in dental implant therapy. The objective of this study was to investigate how different concentrations of immobilized fibroblast growth factor 2 (FGF2) on the titania nanotubular surface influence the response of human gingival fibroblasts (HGFs).Methods: Pure Ti metal was anodized at 20 V to form a vertically organized titanium dioxide nanotube array on which three concentrations of FGF2 (250 ng/mL, 500 ng/mL, or 1000 ng/mL) were immobilized by repeated lyophilization. Surface topography was observed and FGF2 elution was detected using enzyme-linked immunosorbent assay. The bioactivity changes of dissolvable immobilized FGF2 were measured by methyl-thiazolyl-tetrazolium assay. Behavior of HGFs was evaluated using adhesion and methyl-thiazolyl-tetrazolium bromide assays.Results: The FGF2 remained for several days on the modified surface on which HGFs were cultured. Over 90% of the dissolvable immobilized FGF2 had been eluted by Day 9, whereas the FGF2 activity was found to diminish gradually from Day 1 to Day 9. The titania nanotubular surface with an optimal preparing concentration (500 ng/mL) of FGF2 immobilization exhibited improved HGF functions such as cellular attachment, proliferation, and extracellular matrix-related gene expression. Moreover, significant bidirectional as well as concentration- and time-dependent bioactivity was observed.Conclusion: Synergism of the FGF2-impregnated titanium dioxide nanotubular surface revealed good gingival-implant integration, indicating that these materials might have promising applications in dentistry and other biomedical devices.Keywords: dental implants, titanium dioxide nanotube, fibroblast growth factor 2, extracellular matrix, real-time polymerase chain reactio

Heterogeneous ice nucleation correlates with bulk-like interfacial water

Establishing a direct correlation between interfacial water and heterogeneous ice nucleation (HIN) is essential for understanding the mechanism of ice nucleation. Here, we study the HIN efficiency of polyvinyl alcohol (PVA) surfaces with different densities of hydroxyl groups. We find that the HIN efficiency increases with the decrease of the hydroxyl group density. By explicitly considering that interfacial water molecules of PVA films consist of ‘tightly bound water’, ‘bound water’ and ‘bulk-like water’, we reveal that ‘bulk-like water’ can be correlated directly to the HIN efficiency of surfaces. As the density of hydroxyl groups decreases, ‘bulk-like water’ molecules can rearrange themselves with a reduced energy barrier into ice due to the diminishing constraint by the hydroxyl groups on the PVA surface. Our study not only provides a new strategy on experimentally controlling HIN efficiency but also gives another perspective in understanding the mechanism of ice nucleation, i.e., the phase change efficiency of ‘bulk-like’ interfacial water of a film is a predictor for the HIN efficiency of that film

Assess and Summarize: Improve Outage Understanding with Large Language Models

Cloud systems have become increasingly popular in recent years due to their flexibility and scalability. Each time cloud computing applications and services hosted on the cloud are affected by a cloud outage, users can experience slow response times, connection issues or total service disruption, resulting in a significant negative business impact. Outages are usually comprised of several concurring events/source causes, and therefore understanding the context of outages is a very challenging yet crucial first step toward mitigating and resolving outages. In current practice, on-call engineers with in-depth domain knowledge, have to manually assess and summarize outages when they happen, which is time-consuming and labor-intensive. In this paper, we first present a large-scale empirical study investigating the way on-call engineers currently deal with cloud outages at Microsoft, and then present and empirically validate a novel approach (dubbed Oasis) to help the engineers in this task. Oasis is able to automatically assess the impact scope of outages as well as to produce human-readable summarization. Specifically, Oasis first assesses the impact scope of an outage by aggregating relevant incidents via multiple techniques. Then, it generates a human-readable summary by leveraging fine-tuned large language models like GPT-3.x. The impact assessment component of Oasis was introduced in Microsoft over three years ago, and it is now widely adopted, while the outage summarization component has been recently introduced, and in this article we present the results of an empirical evaluation we carried out on 18 real-world cloud systems as well as a human-based evaluation with outage owners. The results show that Oasis can effectively and efficiently summarize outages, and lead Microsoft to deploy its first prototype which is currently under experimental adoption by some of the incident teams

Methylprednisolone as Adjunct to Endovascular Thrombectomy for Large-Vessel Occlusion Stroke

Importance It is uncertain whether intravenous methylprednisolone improves outcomes for patients with acute ischemic stroke due to large-vessel occlusion (LVO) undergoing endovascular thrombectomy. Objective To assess the efficacy and adverse events of adjunctive intravenous low-dose methylprednisolone to endovascular thrombectomy for acute ischemic stroke secondary to LVO. Design, Setting, and Participants This investigator-initiated, randomized, double-blind, placebo-controlled trial was implemented at 82 hospitals in China, enrolling 1680 patients with stroke and proximal intracranial LVO presenting within 24 hours of time last known to be well. Recruitment took place between February 9, 2022, and June 30, 2023, with a final follow-up on September 30, 2023.InterventionsEligible patients were randomly assigned to intravenous methylprednisolone (n = 839) at 2 mg/kg/d or placebo (n = 841) for 3 days adjunctive to endovascular thrombectomy. Main Outcomes and Measures The primary efficacy outcome was disability level at 90 days as measured by the overall distribution of the modified Rankin Scale scores (range, 0 [no symptoms] to 6 [death]). The primary safety outcomes included mortality at 90 days and the incidence of symptomatic intracranial hemorrhage within 48 hours. Results Among 1680 patients randomized (median age, 69 years; 727 female [43.3%]), 1673 (99.6%) completed the trial. The median 90-day modified Rankin Scale score was 3 (IQR, 1-5) in the methylprednisolone group vs 3 (IQR, 1-6) in the placebo group (adjusted generalized odds ratio for a lower level of disability, 1.10 [95% CI, 0.96-1.25]; P = .17). In the methylprednisolone group, there was a lower mortality rate (23.2% vs 28.5%; adjusted risk ratio, 0.84 [95% CI, 0.71-0.98]; P = .03) and a lower rate of symptomatic intracranial hemorrhage (8.6% vs 11.7%; adjusted risk ratio, 0.74 [95% CI, 0.55-0.99]; P = .04) compared with placebo. Conclusions and Relevance Among patients with acute ischemic stroke due to LVO undergoing endovascular thrombectomy, adjunctive methylprednisolone added to endovascular thrombectomy did not significantly improve the degree of overall disability.Trial RegistrationChiCTR.org.cn Identifier: ChiCTR210005172

Smart materials based on cyclodextrins

In the Introduction Chapter, the field of molecular self-assembly and supramolecular chemistry is introduced. The importance and advantages of supramolecular chemistry with noncovalent interactions to trigger the development of artificial molecular machines and the improvement of materials science is discussed. A brief summary of molecular machines is presented with relevant examples from the literatures. Also introduced are cyclodextrin (CD) and the development of CD based molecular machines and daisy chains. Isothermal titration calorimetry (ITC) and nuclear magnetic resonance (NMR) methods are described and their usage as analytical methods to get insight into the selfassembly behaviour of noncovalent interactions is presented. A brief introduction of amides is presented at the end. In the Discussion and Results Chapter 1, a three station photochemically switchable trans 2rotaxane and its photoisomer cis 2rotaxane were studied under various conditions with the aim of achieving unidirectional motion in a rotaxane. 1D and 2D NMR technology was used to analyze the conformational behaviour of the trans 2rotaxane and cis 2rotaxane. In D2O and methanold4 the CD moves with directional selectively, but which direction could not be determined. The successful preparation of a hetero c2 rotaxane consisting of two different light stimuli hermaphrodites with potential to act as a four-station molecular muscle is presented in Discussion and Results Chapter 2. A combined NMR and UVvisible spectroscopic method was used to analyze the conformation and the photolysis of the hetero c2 rotaxane. The conformation of the hetero c2 rotaxane has the CD sitting over the stilbene and azobenzene moieties. However, the hetero c2 rotaxane was not photolabile in MilliQ H2O upon photoirradiation. The possible explanation and solutions are discussed. The Discussion and Results Chapters 3 to 6 described the design and preparation of three types of the substituted CDs with the aim of creating a molecular daisy chain in solution. trans Cinnamido substituted beta CDs only form c1 complexes in aqueous solution. Chapter 3 investigated the solvent effects on their c1complexes. NMR and ITC experiments suggested that the amount of organic solvent required to dissociate the c1 complex also prevents intermolecular complexation. From this, stilbenylamido-substituted alpha CDs were designed and synthesised towards daisy chains by avoiding the c1 complex. Investigation of alkyl steric effects on the amide isomer ratios, and correlation of this with formation of complexes suggested that trans stilbenylamido substituted alpha CDs only form the c2 complexes in aqueous solution. A mechanically interlocked form of the complex constructed by trans stilbenylamido substituted alpha CDs was prepared and examined. This in turn, gave a c2 rotaxane, which was identified by NMR spectroscopy and Mass spectrometry. Finally, trans cinnamido substituted alpha CDs were designed and used in continued pursuit of a molecular daisy chain. The architectures and sizes formed by cinnamido-substituted alpha CDs were studied by advanced microscopy, NMR spectroscopy and ITC measurements in both aqueous solution and organic solvents. Obtained results clearly reveal the formation of supramolecular structures through daisy chain formation in aqueous solution. Gelation in methanold4 is proposed to be driven by other effects

Simulation of Leakage Characteristics of Combined Seal Structure under Rotational Conditions

In order to reduce fluid leakage and improve the working efficiency of rotational machinery, a three-dimensional (3D) model of combined seal structure (CSS) was established to study the influence of pressure ratio (π, the ratio of the leakage port pressure to the outlet pressure) and rotational speed (n) on the leakage characteristics of CSS with a traditional labyrinth seal structure (LSS) and pocket damping seal structure (PDS) under rotational conditions. Two turbulence models, the standard k-ε model and the SST k-ω model, were used for turbulence closure and the results of the standard k-ε model were found to be more accurate based on comparison with experimental results. The results revealed that under rotational condition, the leakage rates of LSS, CSS and PDS all decreased with the increase in π and n. Under the same axial length of seal structure and π of 0.5 and n of 6000 r/min, the leakage rate of CSS is approximately 8.56% less than LSS, and approximately 0.51% more than PDS. There is a critical value for the influence of n on the leakage rate. The critical n of CSS is close to that of LSS, about 1000 r/min, which is greater than the critical n of 500 r/min for PDS. Finally, the sealing mechanism of CSS was studied using a two-dimensional (2D) model, and was found that the jet structure has a greater influence on the sealing characteristics. Among them, when the ΔP (internal resistance of the device) is the same, the shape of the jet structure, the position of the guide tube and the nozzle radius have a greater impact on the leakage rate, and the shape and length of the extended section have a small effect on the leakage rate