Mesenchymal stem cells (MSCs) can be derived from various adult tissues with multipotent and self‐renewal abilities. The characteristics of presenting no major ethical concerns, having low ...immunogenicity and possessing immune modulation functions make MSCs promising candidates for stem cell therapies. MSCs could promote inflammation when the immune system is underactivated and restrain inflammation when the immune system is overactivated to avoid self‐overattack. These cells express many immune suppressors to switch them from a pro‐inflammatory phenotype to an anti‐inflammatory phenotype, resulting in immune effector cell suppression and immune suppressor cell activation. We would discuss the mechanisms governing the immune modulation function of these cells in this review, especially the immune‐suppressive effects of MSCs.
The pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global crisis. Replication of SARS-CoV-2 requires the viral ...RNA-dependent RNA polymerase (RdRp) enzyme, a target of the antiviral drug remdesivir. Here we report the cryo-electron microscopy structure of the SARS-CoV-2 RdRp, both in the apo form at 2.8-angstrom resolution and in complex with a 50-base template-primer RNA and remdesivir at 2.5-angstrom resolution. The complex structure reveals that the partial double-stranded RNA template is inserted into the central channel of the RdRp, where remdesivir is covalently incorporated into the primer strand at the first replicated base pair, and terminates chain elongation. Our structures provide insights into the mechanism of viral RNA replication and a rational template for drug design to combat the viral infection.
Background： Most studies on enhanced recovery after surgery （ERAS） for gastric cancer exclude patients who received neoadjuvant chemotherapy. Here, we aimed to evaluate whether patients who received ...neoadjuvant chemotherapy can be enrolled into the ERAS program for locally advanced gastric cancer. Methods： From April 2015 to July 2017, 114 patients who received neoadjuvant chemotherapy for locally advanced gastric cancer were randomized into ERAS and standard care （SC） groups. Postoperative length of stay, complications, bowel function, and nutritional status were recorded. Results： The postoperative length of stay of the ERAS group was shorter compared with that of the SC group （5.9 ± 5.6 vs. 8.1 ± 5.3 days, P=0.037）.The postoperative complication rate was 9.3% in the ERAS group and 11.5% in the SC group（P=0.700）.The time to first flatus （2.7 ± 2.0 vs. 4.5 ± 4.6 days, P = 0.010） and time to a semi-liquid diet （3.2 ± 2.1 vs. 6.3 ± 4.9 days, P 〈 0.001） in the ERAS group were shorter compared with those in the SC group. On the 10thday after surgery, the values of weight, total protein, albumin, and prealbumin of the ERAS group were lower compared with those of the SC group. Conclusions： Patients who received neoadjuvant chemotherapy could be enrolled into ERAS programs for locally advanced gastric cancer. The nutritional status of these patients was not adversely affected.
The innate immune system has the capacity to detect 'non-self' molecules derived from pathogens, known as pathogen-associated molecular patterns, via pattern recognition receptors. In addition, an ...increasing number of endogenous host-derived molecules, termed damage-associated molecular patterns (DAMPs), have been found to be sensed by various innate immune receptors. The recognition of DAMPs, which are produced or released by damaged and dying cells, promotes sterile inflammation, which is important for tissue repair and regeneration, but can also lead to the development of numerous inflammatory diseases, such as metabolic disorders, neurodegenerative diseases, autoimmune diseases and cancer. Here we examine recent discoveries concerning the roles of DAMP-sensing receptors in sterile inflammation and in diseases resulting from dysregulated sterile inflammation, and then discuss insights into the cross-regulation of these receptors and their ligands.
Polarized detection has been brought into operation for optics applications in the visible band. Meanwhile, an advanced requirement in short-wave near-infrared (SW-NIR) (700–1100 nm) is proposed. ...Typical IV–VI chalcogenides2D GeSe with anisotropic layered orthorhombic structure and narrow 1.1–1.2 eV band gappotentially meets the demand. Here we report the unusual angle dependences of Raman spectra on high-quality GeSe crystals. The polarization-resolved absorption spectra (400–950 nm) and polarization-sensitive photodetectors (532, 638, and 808 nm) both exhibited well-reproducible cycles, distinct anisotropic features, and typical absorption ratios α y /α x ≈ 1.09 at 532 nm, 1.26 at 638 nm, and 3.02 at 808 nm (the dichroic ratio I py/I px ≈ 1.09 at 532 nm, 1.44 at 638 nm, 2.16 at 808 nm). Obviously, the polarized measurement for GeSe showed superior anisotropic response at around 808 nm within the SW-NIR band. Besides, the two testing methods have demonstrated the superior reliability for each other. For the layer dependence of linear dichroism, the GeSe samples with different thicknesses measured under both 638 and 808 nm lasers identify that the best results can be achieved at a moderate thickness about 8–16 nm. Overall, few-layer GeSe has capacity with the integrated SW-NIR optical applications for polarization detection.
We still know very little about how the human immune system responds to SARS-CoV-2. Here we construct a SARS-CoV-2 proteome microarray containing 18 out of the 28 predicted proteins and apply it to ...the characterization of the IgG and IgM antibodies responses in the sera from 29 convalescent patients. We find that all these patients had IgG and IgM antibodies that specifically bind SARS-CoV-2 proteins, particularly the N protein and S1 protein. Besides these proteins, significant antibody responses to ORF9b and NSP5 are also identified. We show that the S1 specific IgG signal positively correlates with age and the level of lactate dehydrogenase (LDH) and negatively correlates with lymphocyte percentage. Overall, this study presents a systemic view of the SARS-CoV-2 specific IgG and IgM responses and provides insights to aid the development of effective diagnostic, therapeutic and vaccination strategies.
Xenotransplantation is a promising strategy to alleviate the shortage of organs for human transplantation. In addition to the concerns about pig-to-human immunological compatibility, the risk of ...cross-species transmission of porcine endogenous retroviruses (PERVs) has impeded the clinical application of this approach. We previously demonstrated the feasibility of inactivating PERV activity in an immortalized pig cell line. We now confirm that PERVs infect human cells, and we observe the horizontal transfer of PERVs among human cells. Using CRISPR-Cas9, we inactivated all of the PERVs in a porcine primary cell line and generated PERV-inactivated pigs via somatic cell nuclear transfer. Our study highlights the value of PERV inactivation to prevent cross-species viral transmission and demonstrates the successful production of PERV-inactivated animals to address the safety concern in clinical xenotransplantation.
Stretchable and transparent strain sensors based on conductive polymer composites (CPCs) possess potential applications in a variety of fields, including electronic skin, wearable electronics, and ...human motion detection. However, it is still a challenge to prepare CPC-based strain sensors with both good transparency and broad sensing range by a low-cost, facile, and scalable fabrication method. Herein, we report a simple spray deposition and transfer method to fabricate a stretchable and transparent strain sensor based on the sandwich-like polydimethylsiloxane (PDMS)/carbon nanotubes (CNTs)/PDMS composite containing with an ultrathin and uniform conductive layer. The fabricated strain sensors exhibit superb stretchability, good optical transparency, and excellent sensing performances, which can detect both the subtle and large strains with outstanding stability and repeatability. For example, the strain sensor based on PDMS/CNTs/PDMS composite (containing 0.16 mg/cm2 CNTs on the conductive layer) presents a good optical transmittance of 53.1% at 550 nm, broad sensing range of over 130%, and the ability to monitor both the subtle motions of facial expressions and the large motions of human joints, which has great potential applications in human motion detection, wearable electronics, and electronic skin.
Fuel cells (FCs) are being considered as a potential alternative in long term to replace diesel/gasoline combustion engines in vehicles and emergency power sources. However, high cost and slow ...dynamic response of FC still persist as the main hurdles for wider applications. To remedy this problem, an energy storage system with adequate power capacity has to be incorporated. This paper presents a novel control design for FC-battery hybrid power system which enables both active current sharing and power source management control in such hybrid systems. Different hybrid power system structures are investigated and evaluated; dual-converter structure and four modes of operation are defined to provide efficient and sustainable solution to such a hybrid power system. A novel integrated control system with inherent current sharing and generation mode swapping capability is proposed; based on system component status, the control system is able to regulate the output power from each source under different scenarios. The dedicated control system is implemented in a TMS320F2812 DSP, and experimental results for an FC-battery-based uninterruptible power supply are provided to demonstrate the static and dynamic performance of the control system.
This paper presents an automated measurement of spine curvature by using prior knowledge on vertebral anatomical structures in ultrasound volume projection imaging (VPI). This method can be used in ...scoliosis assessment with free-hand 3-D ultrasound imaging. It is based on the extraction of bony features from VPI images using a newly proposed two-fold thresholding strategy, with information of the symmetric and asymmetric measures obtained from phase congruency. The spinous column profile is detected from the segmented bony regions, and it is further used to extract a curve representing spine profile. The spine curvature is then automatically calculated according to the inflection points along the curve. The algorithm was evaluated on volunteers with the different severity of scoliosis. The results obtained using the newly developed method had a good linear correlation with those by the manual method (r ≥ 0.90, p <; 0.001) and X-ray Cobb's method (r = 0.83, p <; 0.001). The bigger variations observed in the manual measurement also implied that the automatic method is more reliable. The proposed method can be a promising approach for facilitating the applications of 3-D ultrasound imaging in the diagnosis, treatment, and screening of scoliosis.
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