Search

Flexible solar cells have a lot of market potential for application in photovoltaics integrated into buildings and wearable electronics because they are lightweight, shockproof and self-powered. Silicon solar cells have been successfully used in large power plants. However, despite the efforts made for more than 50 years, there has been no notable progress in the development of flexible silicon solar cells because of their rigidity1–4. Here we provide a strategy for fabricating large-scale, foldable silicon wafers and manufacturing flexible solar cells. A textured crystalline silicon wafer always starts to crack at the sharp channels between surface pyramids in the marginal region of the wafer. This fact enabled us to improve the flexibility of silicon wafers by blunting the pyramidal structure in the marginal regions. This edge-blunting technique enables commercial production of large-scale (>240 cm2), high-efficiency (>24%) silicon solar cells that can be rolled similarly to a sheet of paper. The cells retain 100% of their power conversion efficiency after 1,000 side-to-side bending cycles. After being assembled into large (>10,000 cm2) flexible modules, these cells retain 99.62% of their power after thermal cycling between −70 °C and 85 °C for 120 h. Furthermore, they retain 96.03% of their power after 20 min of exposure to air flow when attached to a soft gasbag, which models wind blowing during a violent storm.

Jun-Peng Zhang,1,&ast; Jun Shen,2,3,&ast; Yun-Ting Xiang,1,&ast; Xiang-Xin Xing,4 Bing-Xin Kang,5 Chi Zhao,2 Jia-Jia Wu,4 Mou-Xiong Zheng,4,6 Xu-Yun Hua,4,6 Lian-Bo Xiao,2,3 Jian-Guang Xu1,4,7 1School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, People’s Republic of China; 2Department of Orthopedic, Guanghua Hospital of Integrative Chinese and Western Medicine, Shanghai, People’s Republic of China; 3Arthritis Institute of Integrated Traditional Chinese and Western Medicine, Shanghai Academy of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, People’s Republic of China; 4Department of Rehabilitation Medicine, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, People’s Republic of China; 5The First Affiliated Hospital of Henan University of Chinese Medicine, Zhengzhou, People’s Republic of China; 6Department of Traumatology and Orthopedics, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, People’s Republic of China; 7Engineering Research Center of Traditional Chinese Medicine Intelligent Rehabilitation, Ministry of Education, Shanghai, China&ast;These authors contributed equally to this workCorrespondence: Jian-Guang Xu, School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, People’s Republic of China, Email xjg@shutcm.edu.cn Lian-Bo Xiao, Department of Orthopedic, Guanghua Hospital of Integrative Chinese and Western Medicine, 540 Xinhua Road, Changning District, Shanghai, People’s Republic of China, Email xiao_lianbo@163.comIntroduction: Osteoarthritis is a chronic, ongoing disease that affects patients, and pain is considered a key factor affecting patients, but the brain changes during the development of osteoarthritis pain are currently unclear. In this study, we used electroacupuncture (EA) to intervene the rat model of knee osteoarthritis and analyzed the changes in topological properties of brain networks using graph theory.Methods: Sixteen SD rat models of right-knee osteoarthritis with anterior cruciate ligament transection (ACLT) were randomly divided into electroacupuncture intervention group and control group. The electroacupuncture group was intervened on Zusanli (ST36) and Futu (ST32) for 20 min each time, five times a week for 3 weeks, while the control group was applied sham stimulation. Both groups were measured for pain threshold. The small-world properties and node properties of the brain network between the two groups after the intervention were statistically analyzed by graph theory methods.Results: The differences are mainly in the changes in node attributes between the two groups, such as degree centrality, betweenness centrality, and so on in different brain regions (P< 0.05). Both groups showed no small-world characteristics in the brain networks of the two groups. The mechanical thresholds and thermal pain thresholds were significantly higher in the EA group than in the control group (P< 0.05).Conclusion: The study demonstrated that electroacupuncture intervention enhanced the activity of nodes related to pain circuit and relieved pain in osteoarthritis, which provides a complementary basis for explaining the effect of electroacupuncture intervention on pain through graphical analysis of changes in brain network topological properties and helps to develop an imaging model for pain affected by electroacupuncture.Keywords: osteoarthritis, electroacupuncture, pain, spatio-temporal analysis, neural plasticity

Blast furnace gas (BFG) is an important secondary energy in the iron and steel industries, and its efficient and reasonable utilization is the key to improving the economic efficiency of enterprises and the level of energy conservation and emission reduction. Aiming at the problems of difficult accurate modeling on the generation process and difficult prediction of real-time flow, this paper proposes a generation prediction model based on spectrum decomposition. Firstly, the major chemical reactions, production process, and data characteristics of blast furnace are analyzed, and the input variables for the prediction model are reasonably selected based on the correlation analysis results. Then, according to the spectrum characteristics, the BFG data is decomposed into low-frequency and medium-frequency parts by two finite impulse response filters. Next, for the low- and middle-frequency components of data, a low-frequency component prediction model based on the support vector regression, and a middle-frequency component prediction model based on the Elman neural network (ENN) are designed respectively. Finally, we decompose the spectrum of the actual industrial production data and find that the spectrum of the decomposed data basically meets the expected target, which verifies the effectiveness of the finite impulse response filters. In addition, we compare the prediction effect of the designed combined model with other models, such as the support vector regression, the back-propagation neural network, and the ENN. The final experimental results show the correctness, effectiveness, and superiority of the combined model and the spectral decomposition method proposed in this paper.

To study the multiscale interactions between rotational and divergent components of atmospheric motion, a new formulation of spectral budget of rotational kinetic energy (RKE) and divergent kinetic energy (DKE) based on the primitive equations in the pressure coordinate is derived, with four main characteristics: 1) horizontal kinetic energy (HKE) spectral transfer is exactly divided into spectral transfer of RKE and DKE, 2) the exact spectral conversion term between DKE and RKE is constructed, 3) the Coriolis term is considered, and 4) both the baroclinic conversion from available potential energy (APE) and the vertical flux of HKE act only on DKE. With this new formulation, outputs from ERA5 global reanalysis are investigated. At planetary scales, HKE spectral transfer, mainly attributed to β effect, is dominated by downscale DKE transfer. At synoptic scales, it is dominated by an upscale transfer of RKE energized by conversion of DKE mainly due to the Coriolis effect. The ultimate source of DKE in the upper troposphere is conversion of APE, while in the stratosphere it is the vertical flux. At mesoscales, the spectral transfers of RKE and DKE are both downscale, and conversion from RKE to DKE exists at sub-800-km scales in the upper troposphere, which is mainly attributed to the contribution from relative vorticity. At different heights, the intersection scales of RKE and DKE spectra are affected by the scales of positive peaks of the local spectral conversion from DKE to RKE around total wavenumber 10. Significance Statement The purpose of this study is to explore more physical insights on the dynamics underlying the atmospheric energy spectra from the perspective of rotational and divergent components of motion. We derive a new formulation of the spectral rotational and divergent kinetic energy budget in the pressure coordinate for the global atmosphere, with application to ERA5 global reanalysis. Our results reveal the differences of spectral energy budget between rotational and divergent motions at different heights and scales. This new formulation provides a good tool for revealing the multiscale cascade and interaction between atmospheric rotational and divergent motions. Future work should investigate these dynamical processes with higher-resolution simulations and datasets.

A 3D silver(I)-polyoxometalate complex of Ag6[MnMo9O32]·4H2O was designed to realize the the elusive label-free SERS quantitative analysis for hydrazine, by which the ratiometric IMn-O/IMo-O signals are proportional to hydrazine concentrations.

Perovskite solar cells (PSCs) are studied in low-intensity low-temperature (LILT) conditions before and after low energy proton irradiation to characterize device performance at deep space mission-relevant light intensities and temperatures.

Myeloid-derived suppressor cells (MDSCs) are heterogeneous immature cells and natural inhibitors of adaptive immunity. Metabolic fitness of MDSCs is fundamental for its suppressive activity toward effector T cells. Our previous studies showed that the number and inhibitory function of MDSCs were impaired in patients with immune thrombocytopenia (ITP) compared with healthy controls. In this study, we analyzed the effects of decitabine on MDSCs from patients with ITP, both in vitro and in vivo. We found that low-dose decitabine promoted the generation of MDSCs and enhanced their aerobic metabolism and immunosuppressive functions. Lower expression of liver kinase 1 (LKB1) was found in MDSCs from patients with ITP, which was corrected by decitabine therapy. LKB1 short hairpin RNA (shRNA) transfection effectively blocked the function of MDSCs and almost offset the enhanced effect of decitabine on impaired MDSCs. Subsequently, anti-CD61 immune-sensitized splenocytes were transferred into severe combined immunodeficient (SCID) mice to induce ITP in murine models. Passive transfer of decitabine-modulated MDSCs significantly raised platelet counts compared with that of phosphate buffered saline–modulated MDSCs. However, when LKB1 shRNA-transfected MDSCs were transferred into SCID mice, the therapeutic effect of decitabine in alleviating thrombocytopenia was quenched. In conclusion, our study suggests that the impaired aerobic metabolism of MDSCs is involved in the pathogenesis of ITP, and the modulatory effect of decitabine on MDSC metabolism contributes to the improvement of its immunosuppressive function. This provides a possible mechanism for sustained remission elicited by low-dose decitabine in patients with ITP.

Common variable immunodeficiency (CVID) is a ‘late-onset’ primary immunodeficiency characterized by variable manifestations and genetic heterogeneity. A monogenic cause of CVID has been reported in 10% of patients. In this study, we identified two novel pathogenic variants implicated in monogenic CVID by whole exome sequencing (WES) analysis: a heterozygous nuclear factor κB subunit 1 (NFKB1) p.G686fs mutation and a homozygous inducible T-cell co-stimulator (ICOS) p.L96Sfs mutation. The predicted crystal models indicated premature truncation of the two mutated proteins. Both variants were demonstrated as loss-of-function mutations and were associated with overlapped manifestations of respiratory fungal infection and splenomegaly. We further performed a detailed assessment of immunologic phenotypes and impaired lymphocyte functions in patients. Moreover, we discovered an association between monoclonal T-large granular lymphocyte proliferation and ICOS-deficient CVID for the first time. These observations lead to a new perspective on the underlying genetic heterogeneity of CVID.

Exosomes generated by BMSCs contribute to functional recovery in ischemic stroke. However, the regulatory mechanism is largely unknown. Exosomes were isolated from BMSCs. Tube formation, MTT, TUNEL, and flow cytometry assays were applied to examine cell angiogenesis, viability, and apoptosis. Protein and DNA interaction was evaluated by ChIP and luciferase assays. LDH release into the culture medium was examined. Infarction area was evaluated by TTC staining. Immunofluorescence staining was applied to examine CD31 expression. A mouse model of MCAO/R was established. BMSC-derived exosomes attenuated neuronal cell damage and facilitated angiogenesis of brain endothelial cells in response to OGD/R, but these effects were abolished by the knockdown of Egr2. Egr2 directly bound to the promoter of SIRT6 to promote its expression. The incompetency of Egr2-silencing exosomes was reversed by overexpression of SIRT6. Furthermore, SIRT6 inhibited Notch signaling via suppressing Notch1. Overexpression of SIRT6 and inhibition of Notch signaling improved cell injury and angiogenesis in OGD/R-treated cells. BMSC-derived exosomal Egr2 ameliorated MCAO/R-induced brain damage via upregulating SIRT6 to suppress Notch signaling in mice. BMSC-derived exosomes ameliorate OGD/R-induced injury and MCAO/R-caused cerebral damage in mice by delivering Egr2 to promote SIRT6 expression and subsequently suppress Notch signaling. Our study provides a potential exosome-based therapy for ischemic stroke.

Pain management following cesarean section remains a challenge, with many puerpera suffering from severe acute postoperative pain. And for a second cesarean section the degree of uterine contraction pain is more severe and frequent than that of a primipara. This study investigated the effect of different doses of nalbuphine combined with sufentanil for postoperative analgesia in patients undergoing a second cesarean section.We prospectively recruited 168 women with a scarred uterus undergoing elective second cesarean section and they were randomly divided into 4 groups by random number extraction. A single intravenous injection of different doses of nalbuphine was given before the intravenous drip of oxytocin, and visual analogue scale (VAS) scores of uterine contraction pain were recorded 10 minutes before intravenous infusion of oxytocin (T1) and 10 minutes (T2), 30 minutes (T3), and 60 minutes (T4) after intravenous infusion of oxytocin. At 4, 8, 12, 24, and 48 hours after patient-controlled intravenous analgesia (PCIA), pain intensity was reassessed using the VAS score.One hundred and sixty patients underwent elective second cesarean section in between December 2020 and May 2021 completed the study. The VAS scores of uterine contractions at T1 and T4 were 3 (1.0), while the VAS scores at T2 and T3 were 7 (1.0), 6 (1.0), 5 (1.0), 5 (1.0) and 8 (1.0), 5 (2.0), 3 (1.0), 3 (0.75). The VAS scores at 12 hours after surgery of nalbuphine10mg and sufentanil (NS1), nalbuphine 10 mg and sufentanil 20 mg (NS2) and nalbuphine 30 mg and sufentanil 20 mg (NS3) were lower than sufentanil (S) group (P0.001). Compared with the S group, total amount of sufentanil and PCIA compression numbers in the NS1, NS2, and NS3 groups at 4-8 and 8-12 hours after surgery decreased (P0.001), with a more significant decrease in the NS2 and NS3 groups than in the NS1 group (P0.001). The NS3 group had a significantly higher incidence of dizziness and sleepiness (P=0.02, P=0.001). Compared with the NS2 and NS3 groups, the incidence of respiratory depression in the S group was significantly higher (P=0.001).A single intravenous injection of nalbuphine 20 mg 10 minutes before the infusion of oxytocin combined with sufentanil 2 µg/kg could be safely used for postoperative analgesia in patients undergoing a second cesarean section and could effectively inhibit uterine contractions induced by oxytocin and reduce adverse reactions.Clinical Trial Registry ChiCTR2100042382.

Background: Upregulation of mitochondrial E3 ubiquitin ligase 1 (Mul1) contributes to brain injury in ischemic stroke due to disturbance of mitochondrial dynamics, and bioinformatics analysis predicts that Mul1 is a potential target of Dipsacoside B. Objective: The aim of the study was to explore whether Dipsacoside B can exert a beneficial effect on brain injury in the ischemic stroke rat via targeting Mul1. Methods: The SD rat brains or PC12 cells were subjected to 2 h-ischemia or 8 h-hypoxia plus 24 h-reperfusion or 24 h-reoxygenation to establish the ischemic stroke rat model in vivo or in vitro, which were treated with Dipsacoside B at different dosages. The brain or PC12 cell injury, relevant protein levels and mitochondrial functions were measured by methods of biochemistry, flow cytometry or Western blot. Results: The neurological dysfunction and brain injury (such as infarction and apoptosis) observed in the ischemic stroke rats were accompanied by increases in Mul1 and dynamin-related protein 1 (Drp1) levels along with decreases in mitofusin 2 (Mfn2) level and ATP production. These effects were attenuated by Dipsacoside B. Consistently, cell injury (necroptosis and apoptosis) occurred in the PC12 cells exposed to hypoxia concomitant with the upregulation of Mul1 and Drp1 along with downregulation of Mfn2 and mitochondrial functions (such as increases in reactive oxygen species production and mitochondrial fission and decreases in mitochondrial membrane potential and ATP production).These phenomena were reversed in the presence of Dipsacoside B. Conclusion: Dipsacoside B can protect the rat brain against ischemic injury via inhibition of Mul1 due to the improvement of mitochondrial function.

International audience

Hepatic ischemia-reperfusion injury (HIRI) can lead to poor prognosis in patients undergoing liver transplantation or extensive liver resection. Maresin conjugate in tissue regeneration 1 (MCTR1) exerts a protective effect in several inflammatory disease models, but its role in HIRI remains unknown. In this study, we examined the effect of MCTR1 on HIRI and its underlying mechanism. HIRI mice and oxygen-glucose deprivation/reperfusion (OGD/R) AML12 cell models were used to evaluate the effects of MCTR1 at different doses on HIRI. Histological changes, inflammatory mediators, and ferroptosis-associated markers including iron content, oxidative stress and antioxidant activity, cell death marker (LDH), and the expression of Nuclear factor erythroid-derived 2-like 2 (NRF2) were analyzed. The results showed that MCTR1 treatment significantly ameliorated liver tissue damage and AST/ALT levels in HIRI mice. It also ameliorated ferroptosis in both HIRI mice and OGD/R AML12 cells, including a decrease in iron content, serum LDH release levels, reactive oxygen species (ROS), MDA, IL-1β levels, and COX2 and transferrin receptor (TFRC) expression. In addition, it increased the levels of IL-10, the antioxidant stress markers SOD and GSH, and the expression of GPX4. With respect to the underlying mechanism, the expression of NRF2 in HIRI mice and OGD/R AML12 cells was significantly inhibited. MCTR1 treatment restored the inhibition of NRF2 expression caused by ischemia-reperfusion, and NRF2 inhibitors significantly inhibited nuclear aggregation of NRF2 promoted by MCTR1. In conclusion, the MCTR1 ameliorates ferroptosis-induced hepatic ischemia-reperfusion injury by promoting NRF2 expression and may represent a therapeutic strategy for treating HIRI.

Understanding human activity and behavior, particularly real-time understanding in video feeds, is one of the most active areas of research in Computer Vision (CV) and Artificial Intelligence (AI) nowadays. To advance the topic of integrating learning engagement research with university teaching practice, accurate and efficient assessment, and analysis of students’ classroom learning behavior engagement is very important. The recently proposed classroom behavior recognition algorithms have some limitations, such as the inability to quickly and accurately identify students’ classroom behaviors because they do not consider the motion information of students between consecutive frames. In recent years, action recognition algorithms based on Convolutional Neural Networks (CNN) have improved significantly. To address the limitations of existing algorithms, in this study, a 3D-CNN is selected as a network model for classroom student behavior recognition, which increases information multisourcing and classroom student localization with high accuracy and robustness. For better analysis of human behavior in videos, the 3D convolution extends the 2D convolution to the spatial–temporal domain. In the proposed system, first of all, a real-time picture stream of each student is obtained by combining real-time target detection and tracking. Then, a deep spatiotemporal residual CNN is used to learn the spatiotemporal features of each student’s behavior, so, as to achieve real-time recognition of classroom behaviors for multistudent targets in classroom teaching scenarios. To verify the effectiveness of the proposed model, different experiments are conducted using the labeled classroom behavior dataset. The experimental results demonstrate that the proposed model exhibits better performance in classroom behavior recognition. The accurate recognition of classroom behaviors can assist the teachers and students to understand the classroom learning situation and help to promote the development of smart classroom.

The era of Industry 4.0 brings about qualitative changes to the economy and society as well as poses new challenges to Chinese education, personnel training, and future development. It is the responsibility of Chinese educational institutions, researchers, government departments, and enterprises to adapt to the changes in science and technology, the market, and the society; to meet the needs of teachers, parents, and students; to understand the current situation of online Chinese education; to connect with the outside world; and ultimately to create a connection with a broader ecosystem of Chinese education to meet the learning needs of Chinese learners around the world.

Zigbee is a very popular technology for Internet of things (IoT) networks mainly because of its low power consumption and low-cost features. It shares the unlicensed 2.4 GHz Industrial, Scientific, and Medical (ISM) radio band with other wireless networks such as Wi-Fi. Usually, Zigbee and Wi-Fi networks coexist in indoor environments for their respective applications. Hence, the coexistence introduces interference for both types of networks lowering the performance of the networks, but Zigbee suffers more significant performance losses because of its lower transmission power than Wi-Fi. Since the number of IoT devices is increasing at an unprecedented rate due to numerous emerging applications and thus making the indoor environments very populous, the peaceful coexistence between Zigbee and Wi-Fi networks in proximity becomes an important research study. For this purpose, this paper presents a comprehensive performance study of a Zigbee network in the presence of a Wi-Fi interference network in a real-life apartment-based indoor environment where Wi-Fi access points of dense neighbors exist. The experiments were done in a XBee module-based Zigbee network for measuring the received signal strength indicator (RSSI), packet drop rate (PDR), and loopback throughput with and without nearby Wi-Fi traffic introduced on purpose. Various networking parameters such as the operating channels, the distances between Zigbee devices and Wi-Fi devices, the transmit timeout of Zigbee packets, and the transmission power of the Zigbee transmitter have been used in the experiments to study the network performance. Our results show that in the deployment of IoT networks in a smart home, radio interference from neighboring homes would not be an important factor, but serious considerations may need to be taken inside the same home. The experimental observations of this paper can serve as a good reference study for Zigbee network deployments in real indoor environments, particularly when interference sources are present in proximity.

Background: Acupuncture has been wildly applied for cerebral ischemia treatment in China for thousands of years, while the specific mechanism remains uncertain. Recently, many studies have shown that acupuncture promotes angiogenesis after ischemia occurs. Here, we examined the effect of electro-acupuncture (EA) exosomes on angiogenesis in hypoxia-induced human umbilical vein endothelial cells (HUVECs). Objective: To investigate whether EA exosomal miR-210 promotes angiogenesis in the hypoxiainduced HUVECs via the HIF-1α/VEGF/Notch 1 signal pathway. Methods: The middle cerebral artery occlusion (MCAO) model was established and treated with EA therapy. Then, exosomes were identified and isolated from rats' plasma in the MCAO+EA group by transmission electron microscopy (TEM), surface markers expressions, and PKH26 reagent. MiR- 210 mimic, miR-210 inhibitor, and HIF-1α were transfected. Flow cytometry, CCK-8 assay, and Transwell assay were conducted to assess the migration, apoptosis, and proliferation of each group of cells. Western blot and quantitative PCR were performed to detect the CD34, HIF-1α, VEGF, Notch 1, and miR-210 expression levels in each group. Results: MiR-210 was significantly upregulated in exosomes of the MCAO plasma, and further enhanced by EA therapy. EA-EXOs and miR-210 mimic inhibited cell apoptosis, promoted cell proliferation and cell migration in hypoxia-induced HUVECs. However, the miR-210 inhibitor reversed the proliferation and migration number induced by EA-EXOs. Besides, EA-EXOs and miR- 210 mimic further enhanced those HIF-1α, VEGF, and Notch 1 levels compared to the hypoxia treatment only. Silencing HIF-1α or miR-210 reversed the high expressions of those three angiogenic factors induced by hypoxia and EA-EXO. qPCR showed similar trends with their relative mRNAs. To analyze these associations quantificationally, Spearman's rank correlation coefficient was calculated. As revealed by results, the expression of proteins and mRNA were highly correlative with each other. Conclusions: These results indicated that EA-EXO miR-210 promotes angiogenesis in hypoxia conditions via HIF-1α/VEGF/Notch 1 signal pathway.