Influence of magnetic field on electron beam-induced Coulomb explosion of gold microparticles in transmission electron microscopy.

In this work we instigated the fragmentation of Au microparticles supported on a thin amorphous carbon film by irradiating them with a gradually convergent electron beam inside the Transmission Electron Microscope. This phenomenon has been generically labeled as "electron beam-induced fragmentation" or EBIF and its physical origin remains contested. On the one hand, EBIF has been primarily characterized as a consequence of beam-induced heating. On the other, EBIF has been attributed to beam-induced charging eventually leading to Coulomb explosion. To test the feasibility of the charging framework for EBIF, we instigated the fragmentation of Au particles under two different experimental conditions. First, with the magnetic objective lens of the microscope operating at full capacity, i.e. background magnetic field B=2 T, and with the magnetic objective lens switched off (Lorenz mode), i.e. B=0 T. We observe that the presence or absence of the magnetic field noticeably affects the critical current density at which EBIF occurs. This strongly suggests that magnetic field effects play a crucial role in instigating EBIF on the microparticles. The dependence of the value of the critical current density on the absence or presence of an ambient magnetic field cannot be accounted for by the beam-induced heating model. Consequently, this work presents robust experimental evidence suggesting that Coulomb explosion driven by electrostatic charging is the root cause of EBIF.

Operando Studies of Bismuth Nanoparticles Embedded in N, O-Doped Porous Carbon for High-Performance Potassium-Ion Hybrid Capacitor.

A highly viable alternative to lithium-ion batteries for stationary electrochemical energy-storage systems is the potassium dual-ion hybrid capacitor (PIHC), especially toward fast-charging capability. However, the sluggish reaction kinetics of negative electrode materials seriously impedes their practical implementation. In this paper, a new negative electrode Bi@RPC (Nano-bismuth confined in nitrogen- and oxygen-doped carbon with rationally designed pores, evidenced by advanced characterization) is developed, leading to a remarkable electrochemical performance. PIHCs building with the active carbon YP50F positive electrode result in a high operation voltage (0.1-4 V), and remarkably well-retained energy density at a high-power density (11107 W kg-1 at 98 Wh kg-1 ). After 5000 cycles the proposed PHICs still show a superior capacity retention of 92.6%. Moreover, a reversible mechanism of "absorption-alloying" of the Bi@RPC nanocomposite is revealed by operando synchrotron X-ray diffraction and Raman spectroscopy. With the synergistic potassium ions storage mechanism arising from the presence of well-structured pores and nano-sized bismuth, the Bi@RPC electrode exhibits an astonishingly rapid kinetics and high energy density. The results demonstrate that PIHCs with Bi@RPC-based negative electrode is the promising option for simultaneously high-capacity and fast-charging energy storage devices.

Strong Exciton-Phonon Coupling as a Fingerprint of Magnetic Ordering in van der Waals Layered CrSBr.

The layered, air-stable van der Waals antiferromagnetic compound CrSBr exhibits pronounced coupling among its optical, electronic, and magnetic properties. As an example, exciton dynamics can be significantly influenced by lattice vibrations through exciton-phonon coupling. Using low-temperature photoluminescence spectroscopy, we demonstrate the effective coupling between excitons and phonons in nanometer-thick CrSBr. By careful analysis, we identify that the satellite peaks predominantly arise from the interaction between the exciton and an optical phonon with a frequency of 118 cm-1 (∼14.6 meV) due to the out-of-plane vibration of Br atoms. Power-dependent and temperature-dependent photoluminescence measurements support exciton-phonon coupling and indicate a coupling between magnetic and optical properties, suggesting the possibility of carrier localization in the material. The presence of strong coupling between the exciton and the lattice may have important implications for the design of light-matter interactions in magnetic semiconductors and provide insights into the exciton dynamics in CrSBr. This highlights the potential for exploiting exciton-phonon coupling to control the optical properties of layered antiferromagnetic materials.

Neutralizing Antibody Responses against Five SARS-CoV-2 Variants and T Lymphocyte Change after Vaccine Breakthrough Infections from the SARS-CoV-2 Omicron BA.1 Variant in Tianjin, China: A Prospective Study.

Objective: To investigate whether Omicron BA.1 breakthrough infection after receiving the SARS-CoV-2 vaccine could create a strong immunity barrier. Methods: Blood samples were collected at two different time points from 124 Omicron BA.1 breakthrough infected patients and 124 controls matched for age, gender, and vaccination profile. Live virus-neutralizing antibodies against five SARS-CoV-2 variants, including WT, Gamma, Beta, Delta, and Omicron BA.1, and T-lymphocyte lymphocyte counts in both groups were measured and statistically analyzed. Results: The neutralizing antibody titers against five different variants of SARS-CoV-2 were significantly increased in the vaccinated population infected with the Omicron BA.1 variant at 3 months after infection, but mainly increased the antibody level against the WT strain, and the antibody against the Omicron strain was the lowest. The neutralizing antibody level decreased rapidly 6 months after infection. The T-lymphocyte cell counts of patients with mild and moderate disease recovered at 3 months and completely returned to the normal state at 6 months. Conclusion: Omicron BA.1 breakthrough infection mainly evoked humoral immune memory in the original strain after vaccination and hardly produced neutralizing antibodies specific to Omicron BA.1. Neutralizing antibodies against the different strains declined rapidly and showed features similar to those of influenza. Thus, T-lymphocytes may play an important role in recovery.

Metavirome of 31 tick species provides a compendium of 1,801 RNA virus genomes.

The increasing prevalence and expanding distribution of tick-borne viruses globally have raised health concerns, but the full repertoire of the tick virome has not been assessed. We sequenced the meta-transcriptomes of 31 different tick species in the Ixodidae and Argasidae families from across mainland China, and identified 724 RNA viruses with distinctive virome compositions among genera. A total of 1,801 assembled and complete or nearly complete viral genomes revealed an extensive diversity of genome architectures of tick-associated viruses, highlighting ticks as a reservoir of RNA viruses. We examined the phylogenies of different virus families to investigate virome evolution and found that the most diverse tick-associated viruses are positive-strand RNA virus families that demonstrate more ancient divergence than other arboviruses. Tick-specific viruses are often associated with only a few tick species, whereas virus clades that can infect vertebrates are found in a wider range of tick species. We hypothesize that tick viruses can exhibit both 'specialist' and 'generalist' evolutionary trends. We hope that our virome dataset will enable much-needed research on vertebrate-pathogenic tick-associated viruses.

Microbatteries with twin-Swiss-rolls redefine performance limits in the sub-square millimeter range.

To maintain the downscaling of microelectronic devices with footprints less than one square millimeter, next-generation microbatteries should occupy the same area and deliver adequate energy for running a new generation of multi-functional microautonomous systems. However, the current microbattery technology fails in accomplishing this task because the micrometer-sized electrodes are not compatible with on-chip integration protocols and technologies. To tackle this critical challenge, an on-chip Swiss-roll microelectrode architecture is employed that exploits the self-assembly of thin films into ultra-compact device architectures. A twin-Swiss-roll microelectrode on a chip occupies a footprint of 0.045 mm2 and delivers an energy density up to 458 µW h cm-2. After packaging, the footprint of a full cell increases to 0.11 mm2 with a high energy density of 181 µW h cm-2. The volumetric energy density excluding the chip thickness is 16.3 mW h cm-3. These results open opportunities for deploying microbatteries as energy and power sources to drive smart dust microelectronics and microautonomous systems.

On-chip integrated process-programmable sub-10 nm thick molecular devices switching between photomultiplication and memristive behaviour.

Molecular devices constructed by sub-10 nm thick molecular layers are promising candidates for a new generation of integratable nanoelectronic applications. Here, we report integrated molecular devices based on ultrathin copper phthalocyanine/fullerene hybrid layers with microtubular soft-contacts, which exhibit process-programmable functionality switching between photomultiplication and memristive behaviour. The local electric field at the interface between the polymer bottom electrode and the enclosed molecular channels modulates the ionic-electronic charge interaction and hence determines the transition of the device function. When ions are not driven into the molecular channels at a low interface electric field, photogenerated holes are trapped as electronic space charges, resulting in photomultiplication with a high external quantum efficiency. Once mobile ions are polarized and accumulated as ionic space charges in the molecular channels at a high interface electric field, the molecular devices show ferroelectric-like memristive switching with remarkable resistive ON/OFF and rectification ratios.

Direct Thermal Enhancement of Hydrogen Evolution Reaction of On-Chip Monolayer MoS2.

MoS2 has drawn great attention as a promising alternative to Pt-based catalysts for the hydrogen evolution reaction (HER). However, it suffers from sluggish kinetics to drive the HER process because of inert basal planes. Here, an on-chip MoS2 monolayer (MoS2 ML) HER reactor was designed and fabricated to reveal direct thermal enhancement of MoS2 ML for the HER. The thermal effects generated efficient electron transfer in the atomic MoS2 ML and at the interface between the electrolyte and the catalyst, leading to enhanced HER activity. The MoS2 ML measured at a higher temperature (60 °C) possesses a significantly enhanced HER activity with a lower overpotential (90 mV at current densities of 10 mA cm-2), lower Tafel slope (94 mV dec-1), and higher turnover frequency (73 s-1 at an overpotential of 125 mV) compared to the results obtained at room temperature. More importantly, the findings are attractive toward understanding the thermal effect on 2D monolayers as well as the development of next-generation electrocatalysts.

Stamping Fabrication of Flexible Planar Micro-Supercapacitors Using Porous Graphene Inks.

High performance, flexibility, safety, and robust integration for micro-supercapacitors (MSCs) are of immense interest for the urgent demand for miniaturized, smart energy-storage devices. However, repetitive photolithography processes in the fabrication of on-chip electronic components including various photoresists, masks, and toxic etchants are often not well-suited for industrial production. Here, a cost-effective stamping strategy is developed for scalable and rapid preparation of graphene-based planar MSCs. Combining stamps with desired shapes and highly conductive graphene inks, flexible MSCs with controlled structures are prepared on arbitrary substrates without any metal current collectors, additives, and polymer binders. The interdigitated MSC exhibits high areal capacitance up to 21.7 mF cm-2 at a current of 0.5 mA and a high power density of 6 mW cm-2 at an energy density of 5 µWh cm-2. Moreover, the MSCs show outstanding cycling performance and remarkable flexibility over 10 000 charge-discharge cycles and 300 bending cycles. In addition, the capacitance and output voltage of the MSCs are easily adjustable through interconnection with well-defined arrangements. The efficient, rapid manufacturing of the graphene-based interdigital MSCs with outstanding flexibility, shape diversity, and high areal capacitance shows great potential in wearable and portable electronics.

A risk predictor of restenosis after superficial femoral artery stent implantation: relevance of mean platelet volume.

BACKGROUND: To investigate the relationship between an increase in the pre- and post-operative mean platelet volume (MPV) and superficial femoral artery in-stent restenosis (ISR) rate. METHODS AND RESULTS: We recruited patients that underwent superficial femoral artery stenting for lower extremity arteriosclerosis obliterans at our hospital from March 2015 to March 2018. All patients gave venous blood three days before and following implantation. Doppler ultrasound, computed tomography angiography or digital subtraction angiography were used for regular follow-up examination. Logistic regression was used to identify predictors of ISR after superficial femoral artery stenting. We enrolled 173 patients, of which 34 (19.6%) were determined as having ISR for a mean of 8.9 ± 2.7 months (3-12 months). Neutrophil count, neutrophil ratio, lymphocyte ratio and platelet count pre-implantation, and platelet count and MPV after stent implantation, and the pre- and post-operative mean platelet volume difference (MPVD) and mean platelet volume difference ratio (MPVDR) were all statistically different when comparing the ISR and non-restenosis groups (p < 0.05). A positive correlation was found for post-operative MPV and presence of ISR (r = 0.58; P < 0.001). A MPVD not less than 1.5 fL was associated with an odds ratio of 9.17 (95% CI [3.76 to 22.35]; P < 0.001) for presence of ISR. A MPVDR of not less than 17.9% was associated with an odds ratio of 7.68 (95% CI [3.19 to 18.49]; P < 0.001) for occurrence of ISR. CONCLUSIONS: An increase in pre- and post-operative MPV was correlated with the occurrence of superficial femoral artery ISR.

Where are the theca cells from: the mechanism of theca cells derivation and differentiation.

Mammalian follicles are composed of oocytes, granulosa cells, and theca cells. Theca cells form in the secondary follicles, maintaining follicular structural integrity and secreting steroid hormones. Two main sources of theca cells exist: Wilms tumor 1 positive (Wt1) cells native to the ovary and Gli1 mesenchymal cells migrated from the mesonephros. Normal folliculogenesis is a process where oocytes, granulosa cells, and theca cells constantly interact with and support each other through autocrine and paracrine mechanisms. The proliferation and differentiation of theca cells are regulated by oocyte-derived factors, including growth development factor 9 and bone morphogenetic protein 15, and granulosa cell-derived factors, including desert hedgehog, Indian hedgehog, kit ligand, insulin-like growth factor 1, as well as hormones such as insulin and growth hormones. Current research on the origin of theca cells is limited. Identifying the origin of theca cells will help us to systematically elaborate the mechanisms of follicular formation and development.

Self-Assembled Flexible and Integratable 3D Microtubular Asymmetric Supercapacitors.

The rapid development of microelectronics has equally rapidly increased the demand for miniaturized energy storage devices. On-chip microsupercapacitors (MSCs), as promising power candidates, possess great potential to complement or replace electrolytic capacitors and microbatteries in various applications. However, the areal capacities and energy densities of the planar MSCs are commonly limited by the low voltage window, the thin layer of the electrode materials and complex fabrication processes. Here, a new-type three-dimensional (3D) tubular asymmetric MSC with small footprint area, high potential window, ultrahigh areal energy density, and long-term cycling stability is fabricated with shapeable materials and photolithographic technologies, which are compatible with modern microelectronic fabrication procedures widely used in industry. Benefiting from the novel architecture, the 3D asymmetric MSC displays an ultrahigh areal capacitance of 88.6 mF cm-2 and areal energy density of 28.69 mW h cm-2, superior to most reported interdigitated MSCs. Furthermore, the 3D tubular MSCs demonstrate remarkable cycling stability and the capacitance retention is up to 91.8% over 12 000 cycles. It is believed that the efficient fabrication methodology can be used to construct various integratable microscale tubular energy storage devices with small footprint area and high performance for miniaturized electronics.

[Influence of the Coagulation Mechanism on the Coagulation Performances Using New Composite Coagulants: Role of the Raw Water Characteristics].

To improve the coagulation performances, new composite coagulants were used to treat different water samples. The results indicate that Ca2+ has no significant effects on the removal efficiency for turbidity in the kaolin system. The residual aluminum decreased from 0.15 mg·L-1 to 0.10 mg·L-1 (AlCl3 was used as coagulant and the coagulant dosage was 0.10 mmol·L-1). The presence of Ca2+ led to the decrease of the amount of negative charges in the HA system and the residual aluminum decreased due to the decrease of the complexation between the HA molecules and Al-based coagulants. When the raw water contained BSA molecules and the coagulant dosage was 0.16 mmol·L-1, the flocs formed by PACl with Ca2+ were larger (~50 µm) than the flocs generated by PACl and the settleability also improved. Under alkaline conditions (pH=8.5), the DOC concentration decreased after coagulation process by~0.2-0.6 mg·L-1 and the residual aluminum decreased by~0.4-0.7 mg·L-1 using composite coagulants. Under acidic conditions (pH=5.5), the concentrations of DOC and residual aluminum did not significantly differ.

G protein-coupled estrogen receptor is involved in the anti-inflammatory effects of genistein in microglia.

BACKGROUND: Genistein (GEN), a phytoestrogen that is extracted from leguminous plants, can bind to estrogen receptor and exert biological effects. G protein-coupled estrogen receptor (GPER), a novel membrane estrogen receptor, has been reported to be involved in the anti-inflammatory process. In the present study, using BV2 microglial cell line and primary microglial culture, we evaluated the involvement of GPER in the anti-inflammatory effects of genistein against lipopolysaccharide (LPS)-induced microglia activation. METHODS: The anti-inflammatory effects of genistein were investigated in LPS-induced microglial activation in murine BV2 microglial cell line and primary microglial culture. Anti-inflammatory properties of genistein were determined by MTT, real time PCR, ELISA and western blot analysis. The pharmacological blockade and lentivirus-mediated siRNA knockdown of GPER were used to study the underlying mechanism. RESULTS: The results showed that genistein exerted inhibitory effects on LPS-induced expressions of cyclooxygenase-2 (COX-2), inducible nitric oxide (iNOS), tumor necrosis factor-α (TNF-α), interleukin-1 ß (IL-1ß) and interleukin-6 (IL-6). Pre-treatment with GPER antagonist G15 could significantly block the anti-inflammatory effects of genistein. Moreover, the inhibitory effects of genistein on LPS-induced activation of MAPKs and NF-κB signaling pathways could also be blocked by G15. Lentivirus-mediated siRNA knockdown of GPER significantly inhibited the anti-inflammatory effects of genistein in BV2 cells. Further study revealed that genistein treatment could increase the gene and protein expressions of GPER in BV2 cells. CONCLUSION: Taken together, these data provide the first evidence that genistein exerts anti-inflammatory effects in microglial cells via GPER activation. These beneficial effects of genistein may represent a new strategy for the treatment of neuroinflammatory diseases.

The bioassay-guided isolation of antifungal saponins from Hosta plantaginea leaves.

Four new steroidal saponins hostaside Ⅰ (1), hostaside Ⅱ (2), hostaside Ⅲ (3), and hostaside Ⅳ (4), together with five known steroidal saponins (5-9), were isolated by the bioassay-guided fractionation from the leaves of Hosta plantaginea (Lam.) Aschers, a worldwide well-known ornamental plant. Hostasides Ⅰ and Ⅱ showed significant antifungal activities, and they could inhibit the growth of Candida albicans and Fusarium oxysporium with MIC values as low as 4 µg/ml.

Transition-Metal-Doped p-Type ZnO Nanoparticle-Based Sensory Array for Instant Discrimination of Explosive Vapors.

The development of portable, real-time, and cheap platforms to monitor ultratrace levels of explosives is of great urgence and importance due to the threat of terrorism attacks and the need for homeland security. However, most of the previous chemiresistor sensors for explosive detection are suffering from limited responses and long response time. Here, a transition-metal-doping method is presented to remarkably promote the quantity of the surface defect states and to significantly reduce the charge transfer distance by creating a local charge reservoir layer. Thus, the sensor response is greatly enhanced and the response time is remarkably shortened. The resulting sensory array can not only detect military explosives, such as, TNT, DNT, PNT, PA, and RDX with high response, but also can fully distinguish some of the improvised explosive vapors, such as AN and urea, due to the huge response reaching to 100%. Furthermore, this sensory array can discriminate ppb-level TNT and ppt-level RDX from structurally similar and high-concentration interfering aromatic gases in less than 12 s. Through comparison with the previously reported chemiresistor or Schottky sensors for explosive detection, the present transition-metal-doping method resulting ZnO sensor stands out and undoubtedly challenges the best.

Haploidentical hematopoietic stem cell transplantation for leukemia in 23 cases / 中国组织工程研究

BACKGROUND:Al ogeneic hematopoietic stem cel transplantation (HSCT) is one of the effective methods in the treatment of leukemia. The haploidentical HSCT is an option for the patients who need a HSCT without a human leukocyte antigen (HLA)-matched donor. OBJECTIVE:To study the clinical efficacy of HLA-haploidentical HSCT on leukemia and its complications. METHODS:A total of 23 patients (4 cases of acute lymphoblastic leukemia, 12 of acute myelogenous leukemia, and 7 of chronic granulocytic leukemia) who had been treated with HLA-haploidentical HSCT from November 2007 to March 2015 were enrol ed. Conditioning regimen I was set as cyclohexyl nitrosourea+cytarabine+busulfan+cyclophosphamide; regimen II as cyclophosphamide+total body irradiation;regimen III as fludarabine+cytarabine+busulfan+cyclophosphamide; and regimen IV as busulfan+cyclophosphamide. Cyclosporin A, mycophenlate mofetil, antithymocyte globulin and methotrexate were used to prevent graft-versus-host disease (GVHD). Hematopoietic remodeling, complications and prognosis were observed in al patients undergoing HLA-haploidentical HSCT. RESULTS AND CONCLUSION:Of the 23 patients, 22 achieved reconstitution of the granulocyte series, and 19 achieved reconstruction of the megakaryocyte series. Additional y, there were 7 cases of acute GVHD and 4 of chronic GVHD. Transplant-related mortality was 22%(5/23) within 100 days post transplantation including graft failure, acute GVHD, intracranial hemorrhage and disseminated infections. There were 14 cases of disease-free survival from 100 days to 24 months post transplantation, 2 cases of death due to GVHD and fungal infection, or recurrence and chronic GVHD, and 2 cases of recurrence under treatment. These findings indicate that HLA-haploidentical HSCT is an effective approach for the treatment of patients with leukemia, which is worth further investigation in clinical practice.

Sediment prokaryote communities in different sites of eutrophic Lake Taihu and their interactions with environmental factors.

To investigate the temporal variation of the sediment prokaryote communities and their relation with the rapid increase of algae population in Taihu, a shallow eutrophic freshwater Lake, water and surface sediments were sampled from seven sites in different stages of algal bloom. The physicochemical characterization revealed positive correlations among the nutrient (N, P) parameters in the water and sediments, as well as TN/TP ratio 30.79 in average in water and 0.13 in sediments, demonstrating that P content was the limit factor for bloom in Taihu and sediment was an important nutrient resource for the water body. T-RFLP analysis of 16S rRNA genes revealed a diversity decrease of sediment prokaryotic communities along the bloom. The bacterial communities in sediments were more sensitive and shaped by the temporal changes, while archaea were more sensitive to the trophic level. The pyrosequencing data showed clear spatial and temporal changes in diversity of sediment bacteria. Betaproteobacteria was the most abundant group in all the samples, following by Delta-, Gama- and Alpha-proteobacteria, Acidobacteria, Chlorobi, Chloroflexi etc. At the genus level, Thiobacillus and Sulfuricurvum were the most dominant groups in the sediments, and the increase of Thiobacillus abundance in February might be used as bioindicator for the subsequent bloom. In addition, NO3 (-)-N was evidenced to be the main factor to regulate the bacterial community structure in the sediments. These results offered some novel and important data for the evaluation and predict the algal bloom in Taihu and can be reference for other shallow fresh water lakes.

[Spatiotemporal variation patterns of water quality of Taoranting Lake, Beijing of China].

By the methods of cluster analysis, discriminant analysis, and factor analysis, this paper studied the spatiotemporal variations of water quality of Taoranting Lake, a typical eutrophic urban landscape lake in Beijing, from March to November 2011. At temporal scale, the water quality of the Lake could be grouped into three periods which corresponded to the rainy season, normal season, and dry season in Beijing, respectively, reflecting an obvious temporal variation. At spatial scale, the water quality of the Lake at five sampling sites could be grouped into two groups, implying the different pollution degree. Water temperature, pH, transparency (SD), CODMn, total suspended solid (TSS) , and Chl-a content were the main factors affecting the temporal variation of the water quality, and the eutrophication of the water body was mainly controlled by the water temperature and Chl-a, total nitrogen, and total phosphorous contents. The effects of TSS and organic pollution should be also paid more attention.