Based on the data of Chinese manufacturing firms from 2000 to 2006, this study takes the university enrolment expansion policy implemented by the Chinese government in 1999 as a quasi-natural ...experiment, and uses the difference-in-difference (DID) method to identify the effect of human capital expansion on the ratio of domestic value added in exports to gross exports (DVAR) of firms. Results show that human capital expansion significantly improves the firms' DVAR through the 'intermediate product substitution' channel (promoting firms to use more domestic intermediate inputs to replace imported intermediate inputs in production) and the 'markup' channel (promoting the increase of firms' markup). At the same time, significant heterogeneity exists in the effects of human capital expansion on the DVAR of different types of firms. These results provide new empirical evidence from the perspective of firm DVAR for further understanding of the microeconomic effects of human capital.
In this study, we analyse how export product quality affects the markup of firms. First, on the basis of the heterogeneous firm trade model, we clarify the internal mechanism of the effect of export ...product quality on the markup of firms through the channels of firm marginal production cost and product pricing. Second, using the micro data of Chinese firms from 2000 to 2007 and by estimating firm-level markup and export product quality, we construct a dynamic panel model to empirically analyze the impact of export product quality on the markup of the Chinese firms and mechanism of the impact. Results of the empirical analysis support the prediction of the theoretical model, that is, improvement of export product quality will positively affect the markup of firms by increasing their marginal cost of production and product pricing. From the product quality perspective, we provide new insights for understanding the impact of the export market on the markup of firms.
Reactive oxygen species (ROS) depletion and low ROS production that result from the intratumoral redox metabolism equilibrium and low energy conversion efficiency from ultrasound mechanical energy to ...ROS‐represented chemical energy, respectively, are two vital inhibitory factors of sonodynamic therapy (SDT). To address the two concerns, a tumor metabolism‐engineered composite nanoplatform capable of intervening intratumoral ROS metabolism, breaking the redox equilibrium, and reshaping the tumor microenvironment is constructed to reinforce SDT against tumors. In this metabolism‐engineered nanoplatform, Nb2C nanosheets serve as the scaffold to accommodate TiO2 sonosensitizers and l‐buthionine‐sulfoximine. Systematic experiments show that such nanoplatforms can reduce ROS depletion via suppressing glutathione synthesis and simultaneously improving ROS production via the Nb2C‐enhanced production and separation of electron–hole pairs. Contributed by the combined effect, net ROS content can be significantly elevated, which results in the highly efficient anti‐tumor outcomes in vivo and in vitro. Moreover, the combined design principles, that is, tumor metabolism modulation for reducing ROS depletion and electron–hole pair separation for facilitating ROS production, can be extended to other ROS‐dependent therapeutic systems.
An intratumoral metabolism modulation‐engineered sonodynamic therapy (SDT)‐based nanoplatform has been constructed to break the reactive oxygen species (ROS)‐involved redox metabolism equilibrium and reshape the tumor microenvironment for reducing ROS depletion, and simultaneously facilitate ROS production via enhancing the production and separation of electron–hole pairs, which enables the significantly improved net content of ROS for highly‐efficient SDT against tumors.
An α‐difluoroalkylation of benzyl amines with trifluoromethylarenes is disclosed herein. This protocol is characterized by its operational simplicity, excellent chemoselectivity and broad scope—even ...with advanced synthetic intermediates—, thus offering a new entry point to medicinally‐relevant α‐difluoroalkylated amines from simple, yet readily accessible, precursors.
A highly modular technique that streamlines the synthesis of α‐difluoroalkylated amines from benzyl amines and trifluoromethylarenes has been developed. This protocol demonstrates remarkable operational simplicity, excellent chemoselectivity, and wide applicability, including with advanced synthetic intermediates, thus providing a novel pathway to access medicinally‐relevant α‐difluoroalkylated amines from readily available and simple precursors.
1,2‐Bisphosphines have been identified as one class of important and powerful chiral ligands in asymmetric catalysis with transition metals. Herein, a copper(I)‐catalyzed asymmetric ...hydrophosphination of α,β‐unsaturated phosphine sulfides was developed with the assistance of “soft–soft” interaction between copper(I)‐catalyst and the phosphine sulfide moiety, which afforded 1,2‐bisphosphine derivatives with diversified electronic nature and steric hindrance in high to excellent yields with high to excellent enantioselectivity. Moreover, the challenging catalytic asymmetric hydrophosphination/protonation reaction was achieved with excellent enantioselectivity. Strikingly, the dynamic kinetic resolution of racemic diarylphosphines was also successfully carried out with high to excellent diastereo‐ and enantioselectivities. Interestingly, the nucleophilic copper(I)‐diphenylphosphide species was characterized by 31P NMR spectrum and mass spectrum. At last, three products were transformed to chiral 1,2‐bisphosphines, which were employed as ligands in Rh‐catalyzed asymmetric hydrogenation of α‐amino‐α,β‐unsaturated ester. The α‐amino acid derivative was produced in high enantioselectivity, which demonstrated the utility of the present methodology.
A catalytic asymmetric conjugate hydrophosphination of α,β‐unsaturated phosphine sulfides with diarylphosphines allows rapid construction of chiral 1,2‐bisphosphine derivatives with diversified electronic nature and steric hindrance. This reaction is facilitated by the “soft–soft” interaction between copper(I) catalysts and phosphine sulfides.
In 1999, the Chinese government implemented the university enrollment expansion policy, which resulted in the rapid increase in college graduates in 2003. This study conducts a quasi-natural ...experiment and uses the difference-in-difference (DID) method to deeply analyze the impact of human capital expansion on firms' export product quality. Robustness tests revealed that human capital expansion significantly improves the export product quality of Chinese manufacturing firms. Fixed asset investment and innovation of firms must be promoted for human capital expansion to improve firms' export product quality. A significant amount of heterogeneity exists in how human capital expansion impacts the export product quality across various types of firms.
The outbreak of coronavirus disease 2019 (COVID‐19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), has been recently declared a pandemic by the World Health ...Organization. In addition to its acute respiratory manifestations, SARS‐CoV‐2 may also adversely affect other organ systems. To date, however, there is a very limited understanding of the extent and management of COVID‐19‐related conditions outside of the pulmonary system. This narrative review provides an overview of the current literature about the extrapulmonary manifestations of COVID‐19 that may affect the urinary, cardiovascular, gastrointestinal, hematological, hematopoietic, neurological, or reproductive systems. This review also describes the current understanding of the extrapulmonary complications caused by COVID‐19 to improve the management and prognosis of patients with COVID‐19.
Highlights
SARS‐CoV‐2 appears to adversely affect not only the respiratory system but also several other organ systems, including the urinary, cardiovascular, GI, and neurological systems.
To date, however, there is very limited understanding of the extent and management of COVID‐19‐related conditions outside of the pulmonary system.
Further research is needed to better understand the underlying mechanisms linking SARS‐CoV‐2 with the occurrence of multiple extra‐pulmonary complications.
Abstract
Background
Papillary thyroid microcarcinoma (PTMC) has become a main cause of the extremely high incidence of thyroid carcinoma. This study aimed to evaluate the longer-term effectiveness of ...ultrasound (US)-guided microwave ablation (MWA) for treatment of low-risk PTMC with a large population.
Methods
This prospective study was approved by ethics committee of our institution. MWA was performed under US-guidance for 119 unifocal PTMC patients without clinically cervical or distant metastasis. The target ablation zone exceeded the tumor edge judged by contrast-enhanced US to avoid marginal residue and recurrence. US and thyroid function evaluation were followed at 1, 3, 6, and 12 months after treatment and every 6 to 12 months thereafter. Any adverse event associated with MWA was evaluated.
Results
The follow-up duration after MWA was 37.2 ± 20.9 months (range 12-101 months). Tumor volume decreased significantly from 1.87 ± 1.03 mL immediately after MWA to 0.01 ± 0.04 mL at the final evaluation (P < 0.001), with a mean volume reduction ratio of 99.4 ± 2.2% and 107 cases (93.9%) got complete remission. A patient was detected with cervical lymph node metastasis at 26-month follow-up and underwent 1 additional MWA treatment successfully. No distant metastasis was observed. All the acquired histological pathology results confirmed the absence of residual or recurrent tumor cells after MWA. No delayed complications associated with MWA were encountered for all patients.
Conclusions
Percutaneous MWA is technically feasible for complete PTMC destruction and showed well longer-term effectiveness; thus, it seems to be an effective nonsurgical therapy to complement the current recommendation for selected low-risk PTMC patients.
Abstract
Based on the micro data set of Chinese manufacturing enterprises, this study examines in detail the impact of foreign direct investment on the innovation performance of Chinese local ...enterprises and its mechanism. Results show that foreign direct investment helps to improve the innovation performance of Chinese local enterprises, and spillover effect and competition effect are important ways for foreign direct investment to affect the innovation performance of local enterprises. In addition, the impact of foreign direct investment on the innovation of local enterprises of different types varies. Foreign direct investment has significantly promoted the innovation of high-productivity, capital-intensive, non-coastal, export, and non-state-owned enterprises. This study enriches the research literature on foreign direct investment and enterprise innovation and provides new micro evidence for understanding the impact of foreign direct investment on the innovation performance of local enterprises.
Low quantum yield and aggregation‐mediated quenching are two concerns for fluorescence imaging. However, there are not yet general means available for addressing these issues. Herein, a viscosity ...confinement‐mediated antiaggregation strategy is established to enable the improved fluorescence properties of entrapped fluorophores in dye‐encapsulation nanotechnology including quantum yield, fluorescence lifetime, and photostability. To instantiate this strategy, solid DL‐menthol (DLM) is introduced to disperse entrapped indocyanine green (ICG) fluorophores when coencapsulating DLM and ICG molecules in organic poly(lactic‐co‐glycolic acid) carriers. Depending on the robust ability of highly viscous DLM to augment the migration barrier and diminish diffusion coefficient, ICG aggregation and aggregation‐mediated quenching are demonstrated to be theoretically and experimentally inhibited, resulting in prolonged fluorescence lifetime, increased quantum yield, and facilitated radiative process. Consequently, the fluorescence imaging ability and photostability are significantly improved, enabling the in vitro, cellular‐level, and in vivo fluorescence imaging. More significantly, this solid DLM‐mediated antiaggregation strategy can act as a general method to extend to the intermolecular fluorescence resonance energy transfer (FRET) process and improve FRET efficiency via inhibiting the aggregation‐mediated quenching.
Solid DL‐menthol is introduced into poly(lactic‐co‐glycolic acid) carriers to disperse entrapped fluorophores and establish a viscosity confinement‐mediated antiaggregation strategy for inhibiting quenching and improving fluorescence imaging properties associated with quantum yield, fluorescence lifetime, and photostability via the high viscosity‐mediated migration barrier elevation, which provides a new avenue to improving fluorescence imaging of entrapped fluorophores in dye‐encapsulation nanotechnology.
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