We report a hollow-core negative-curvature fiber (HC-NCF) optical signal amplifier fabricated by the filling of the air microchannels of the fiber with all-inorganic CsPbBr
perovskite nanocrystals ...(PNCs). The optimum fabrication conditions were found to enhance the optical gain, up to +3 dB in the best device. Experimental results were approximately reproduced by a gain assisted mechanism based on the nonlinear optical properties of the PNCs, indicating that signal regeneration can be achieved under low pump powers, much below the threshold of stimulated emission. The results can pave the road of new functionalities of the HC-NCF with PNCs, such as optical amplification, nonlinear frequency conversion and gas sensors.
Background： The lateral pillar of the femoral head is an important site for disease development such as osteonecrosis of the femoral head. The femoral head consists of medial, central, and lateral ...pillars. This study aimed to determine the biomechanical effects of early osteonecrosis in pillars of the femoral head via a finite element （FE） analysis. Methods： A three-dimensional FE model of the intact hip joint was constructed from the image data of a healthy control. Further, a set of six early osteonecrosis models was developed based on the three-pillar classification. The von Mises stress and surface displacements were calculated for all models. Results： The peak values of von Mises stress in the cortical and cancellous bones of normal model were 6.41 MPa and 0.49 MPa, respectively. In models with necrotic lesions in the cortical and cancellous bones, the von Mises stress and displacement of lateral pillar showed significant variability： the stress of cortical bone decreased from 6.41 MPa to 1.51 MPa （76.0% reduction）, while cancellous bone showed an increase from 0.49 MPa to 1.28 MPa （159.0% increase）; surface displacements of cortical and cancellous bones increased from 52.4 μm and 52.1 μm to 67.9 μm （29.5%） and 61.9 μm （18.8%）, respectively. In addition, osteonecrosis affected not only pillars but also adjacent structures in terms of the von Mises stress and surface displacement levels. Conclusions： This study suggested that the early-stage necrosis in the femoral head could increase the risk of collapse, especially in lateral pillar. On the other hand, the cortical part of lateral pillar was found to be the main biomechanical support of femoral head.
Background： Lateral compartmental osteoarthritis （LCOA）, a major complication after medial mobile-bearing unicompartmental knee arthroplasty （UKA）, is highly associated with the increased stress of ...the lateral compartment. This study aimed to analyze the effects on the stress and load distribution of the lateral compartment induced by lower limb alignment and coronal inclination of the tibial component in UKA through a finite element analysis. Methods： Eight three-dimensional models were constructed based on a validated model for analyzing the biomechanical effects of implantation parameters on the lateral compartment after medial Oxford UKA： postoperative lower limb alignment of 3° valgus, neutral and 3° varus, and the inclination of tibial components placed in 4°, 2° valgus, square, and 2° and 4° varus. The contact stress of femoral and tibial cartilage and load distribution were calculated for all models. Results： In the 3° valgus lower limb alignment model, the contact stress of femoral （3.38 MPa） and tibial （3.50 MPa） cartilage as well as load percentage （45.78%） was highest compared to any other model, and was increased by 36.75%, 47.70%, and 27.63%, respectively when compared to 3° varus. In the condition of a neutral position, the outcome was comparable for the different tibial tray inclination models. The inclination did not greatly affect the lateral compartmental stress and load distribution. Conclusions： This study suggested that slightly varus （undercorrection） lower limb alignment might be a way to prevent LCOAin medial mobile-bearing UKA. However, the inclination （4° varus to 4° valgus） of the tibial component in the coronal plane would not be a risk factor for LCOA in neutral position.
Novel T-shaped bolaamphiphiles consisting of a bent 2,5-diphenylethynyl thiophene rigid core with two terminal glycerol units and a lateral n-alkyl chain have been synthesized via Kumuda and ...Sonogashira coupling reactions as key steps. Their liquid crystalline behavior was investigated by polarizing optical microscopy （POM）, differential scanning calorimetry （DSC）, and X-ray diffraction （XRD）. All such bolaamphiphiles can self-organize into square honeycomb LC phases with p4rnm symmetries in the presence of water, UV and PL measurements indicate fluorescent properties making them potential candidates for application in fluorescence sensor devices.
Transition metal dichalcogenide materials have been explored extensively as catalysts to negotiate the hydrogen evolution reaction, but they often run at a large excess thermodynamic cost. Although ...activating strategies, such as defects and composition engineering, have led to remarkable activity gains, there remains the requirement for better performance that aims for real device applications. We report here a phosphorus-doping-induced phase transition from cubic to orthorhombic phases in CoSe
. It has been found that the achieved orthorhombic CoSe
with appropriate phosphorus dopant (8 wt%) needs the lowest overpotential of 104 mV at 10 mA cm
in 1 M KOH, with onset potential as small as -31 mV. This catalyst demonstrates negligible activity decay after 20 h of operation. The striking catalysis performance can be attributed to the favorable electronic structure and local coordination environment created by this doping-induced structural phase transition strategy.
Kaposi's sarcoma (KS), a highly disseminated tumor of hyperproliferative spindle endothelial cells, is the most common AIDS-associated malignancy caused by infection of Kaposi's sarcoma-associated ...herpesvirus (KSHV). KSHV-encoded viral interferon regulatory factor 1 (vIRF1) is a viral oncogene but its role in KSHV-induced tumor invasiveness and motility remains unknown. Here, we report that vIRF1 promotes endothelial cell migration, invasion and proliferation by down-regulating miR-218-5p to relieve its suppression of downstream targets high mobility group box 2 (HMGB2) and cytidine/uridine monophosphate kinase 1 (CMPK1). Mechanistically, vIRF1 inhibits p53 function to increase the expression of DNA methyltransferase 1 (DNMT1) and DNA methylation of the promoter of pre-miR-218-1, a precursor of miR-218-5p, and increases the expression of a long non-coding RNA OIP5 antisense RNA 1 (lnc-OIP5-AS1), which acts as a competing endogenous RNA (ceRNA) of miR-218-5p to inhibit its function and reduce its stability. Moreover, lnc-OIP5-AS1 increases DNA methylation of the pre-miR-218-1 promoter. Finally, deletion of vIRF1 from the KSHV genome reduces the level of lnc-OIP5-AS1, increases the level of miR-218-5p, and inhibits KSHV-induced invasion. Together, these results define a novel complex lnc-OIP5-AS1/miR-218-5p network hijacked by vIRF1 to promote invasiveness and motility of KSHV-induced tumors.
Rapid detection of antibodies to SARS‐CoV‐2 is critical for COVID‐19 diagnostics, epidemiological research, and studies related to vaccine evaluation. It is known that the nucleocapsid (N) is the ...most abundant protein of SARS‐CoV‐2 and can serve as an excellent biomarker due to its strong immunogenicity. This paper reports a rapid and ultrasensitive 3D biosensor for quantification of COVID‐19 antibodies in seconds via electrochemical transduction. This sensor consists of an array of three‐dimensional micro‐length‐scale electrode architecture that is fabricated by aerosol jet 3D printing, which is an additive manufacturing technique. The micropillar array is coated with N proteins via an intermediate layer of nano‐graphene and is integrated into a microfluidic channel to complete an electrochemical cell that uses antibody‐antigen interaction to detect the antibodies to the N protein. Due to the structural innovation in the electrode geometry, the sensing is achieved in seconds, and the sensor shows an excellent limit of detection of 13 fm and an optimal detection range of 100 fm to 1 nm. Furthermore, the sensor can be regenerated at least 10 times, which reduces the cost per test. This work provides a powerful platform for rapid screening of antibodies to SARS‐CoV‐2 after infection or vaccination.
Highlights
This work demonstrates a microfluidic biosensor with 3D printed array electrodes that detects nucleocapsid (N) antibodies to SARS‐CoV‐2 in mere 10‐12 seconds. This breakthrough technology will save lives and help in the management of the ongoing COVID‐19 pandemic.
Infection by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) causes a wide spectrum of syndromes involving multiple organ systems and is primarily mediated by viral spike (S) ...glycoprotein through the receptor‐binding domain (RBD) and numerous cellular proteins including ACE2, transmembrane serine protease 2 (TMPRSS2), kidney injury molecule‐1 (Kim‐1), and neuropilin‐1 (NRP‐1). In this study, we examined the entry tropism of SARS‐CoV‐2 and SARS‐CoV using S protein‐based pseudoviruses to infect 22 cell lines and 3 types of primary cells isolated from respiratory, urinary, digestive, reproductive, and immune systems. At least one cell line or type of primary cell from each organ system was infected by both pseudoviruses. Infection by pseudoviruses is effectively blocked by S1, RBD, and ACE2 recombinant proteins, and more weakly by Kim‐1 and NRP‐1 recombinant proteins. Furthermore, cells with robust SARS‐CoV‐2 pseudovirus infection had strong expression of either ACE2 or Kim‐1 and NRP‐1 proteins. ACE2 glycosylation appeared to be critical for the infections of both viruses as there was a positive correlation between infectivity of either SARS‐CoV‐2 or SARS‐CoV pseudovirus with the level of glycosylated ACE2 (gly‐ACE2). These results reveal that SARS‐CoV‐2 cell entry could be mediated by either an ACE2‐dependent or ‐independent mechanism, thus providing a likely molecular basis for its broad tropism for a wide variety of cell types.
To provide an updated assessment of the safety and efficacy of enhanced recovery after surgery (ERAS) protocols in elective gastric cancer (GC) surgery.
PubMed, Medline, EMBASE, World Health ...Organization International Trial Register, and Cochrane Library were searched up to June 2017 for all available randomized controlled trials (RCTs) comparing ERAS protocols and standard care (SC) in GC surgery. Thirteen RCTs, with a total of 1092 participants, were analyzed in this study, of whom 545 underwent ERAS protocols and 547 received SC treatment.
No significant difference was observed between ERAS and control groups regarding total complications (
= 0.88), mortality (
= 0.50) and reoperation (
= 0.49). The incidence of pulmonary infection was significantly reduced (
= 0.03) following gastrectomy. However, the readmission rate after GC surgery nearly tripled under ERAS (
= 0.009). ERAS protocols significantly decreased the length of postoperative hospital stay (
< 0.00001) and medical costs (
< 0.00001), and accelerated bowel function recovery, as measured by earlier time to the first flatus (
= 0.0004) and the first defecation (
< 0.0001). Moreover, ERAS protocols were associated with a lower level of serum inflammatory response, higher serum albumin, and superior short-term quality of life (QOL).
Collectively, ERAS results in accelerated convalescence, reduction of surgical stress and medical costs, improved nutritional status, and better QOL for GC patients. However, high-quality multicenter RCTs with large samples and long-term follow-up are needed to more precisely evaluate ERAS in radical gastrectomy.
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