Microbial degradation mechanism of historical silk revealed by proteomics and metabolomics.

Archaeological silk undergoes destructive and irreversible changes during the natural process of decay. However, in-depth studies on the influence of this biological factor are still lacking. Here, a combination of proteomics and metabolomics is proposed for the first time to explore the interaction between bacteria and historical silk during biodegradation, which provides information on changes at the molecular level of proteins and bacterial metabolites. Morphological observation revealed biofilms produced by Stenotrophomonas maltophilia and Pseudomonas alcaligenes when cultured in the stationary phase and confirmed severe deterioration of silk. Proteomics showed that S. maltophilia had an unbiased effect on silk fibroin, indicating its ability to disrupt both heavy and light chains, as well as other proteins, while P. alcaligenes showed an affinity for more disordered proteins. Analysis of bacterial metabolites showed that overall activity reduction and significant accumulation of fatty acid and phenol metabolites occurred after silk addition, suggesting that the presence of silk may inhibit the activity of an individual strain. This study provides a new insight into the microbial degradation mechanism of archaeological silk.

Effect of cocooning conditions on the structure, carbon and nitrogen isotope ratios of silks.

The stable isotope technique provides the possibility to trace ancient textiles because the technique is associated with advantages such as trace indication, fast detection, and accurate results. Since different cocooning conditions may impact cocoons even under identical habitats, it is important to investigate the effects of different cocooning temperatures and humidity on the isotope incorporation values in the cocoons. In this study, silk fibers were reeled under different conditions of temperature and humidity, followed by analysis of the secondary structure of cocoon proteins and isotope incorporation patterns. We found that the deviations in carbon isotope values of silk under different cocooning conditions could reach up to 0.76‰, while the deviation in carbon isotope values at different locations of a single silk was 2.75‰. Further, during the cocooning process, depletion of the 13C-isotope at different locations of the silk fibers was observed, reducing the δ13C values. We proposed that the changes in carbon isotopes in silk were related to the content of sericin and silk fibroin in silk. Finally, we did not observe a significant difference in isotope ratios in degummed cocoons. In summary, the 13C isotope was enriched in sericin, whereas 15N was enriched in fibroin, and these findings provide basic information for tracing the provenance of silks.

IntelliSense Bio-Ionotronics Battery for Early Warning of Geological Seepage.

Water seepage-induced geological hazards (SIGHs), including landslides, collapse, debris flow, and ground fissures, often cause substantial human mortality, economic losses, and environmental damage. However, an early warning of geological water seepage remains a significant challenge. A self-powered, cost-effective, reliable, and susceptible SIGH early warning system (SIGH-EWS) is reported herein. This system designed the all-solid, sustainable, fire retardant, and safe-to-use bio-ionotronic batteries to provide a stable power supply for Internet of Things chipsets. Furthermore, the batteries' outstanding humidity and water sensitivity allow sensing of the water seepage emergence. Integrating energy management and wireless communication systems, the SIGH-EWS realizes timely alerts for early water seepage in different water and soil environments with a time resolution in seconds. Based on these merits, the SIGH-EWS demonstrates promising application prospects for early warning of geological disasters and corresponding design strategies that can potentially guide the designs of next-generation geological hazard alarm systems.

A pilot study of stable isotope fractionation in Bombyx mori rearing.

Hydrogen, oxygen, carbon, and nitrogen isotopes derived from three different strains of silkworms at different life stages involved in silkworm rearing, were measured to understand the fractionation characteristics of stable isotopes at different stages of silkworm development, and to trace the movement of these isotopes from food to larva to excrement and finally to silk. We found that silkworm strain had little effect on δ2H, δ18O and δ13C values. However, a large difference was found in the δ15N levels of newly-hatched silkworms between Jingsong Haoyue and Hua Kang No. 3 orthogonal strains, suggesting that the mating and egg laying differences may result in an inconsistent kinetic nitrogen isotope fractionation. The δ13C values of silkworm pupae and silkworm cocoon also displayed significant differences, suggesting that heavy carbon isotopes are greatly fractionated from the larva to the silk during cocoon formation. Overall, these results may be used to clarify the relationship between isotope fractionation and the ecological process of the Bombyx mori and expand our ability to resolve stable isotope anomalies at a small regional-scale level.

Anti-Jamming Strategy for Federated Learning in Internet of Medical Things: A Game Approach.

Federated learning (FL) is a new dawn of artificial intelligence (AI), in which machine learning models are constructed in a distributed manner while communicating only model parameters between a centralized aggregator and client internet-of-medical-things (IoMT) nodes. The performance of such a learning technique can be seriously hampered by the activities of a malicious jammer robot. In this paper, we study client selection and channel allocation along with the power control problem of the uplink FL process in IoMT domain under the presence of a jammer from the perspective of long-term learning duration. We map the interaction between the FL network and the jammer in each learning iteration as a Stackelberg game, in which the jammer acts as the leader and the FL network serves as the follower. We consider the client and channel selection as well as the power control jointly as the strategy of this game. Upon formulating the game, we find the joint best response strategy for both types of players by leveraging the difference of convex (DC) programming approach and the dual decomposition technique. Beside the availability of the complete information to both the players, we also study the problem from the perspective that the FL network knows the partial information of the other player. Extensive simulations have been conducted to verify the effectiveness of the proposed algorithms in the jamming game.

Characteristics of the cylindrical reflex triode driven by a four-stage linear transformer driver.

A cylindrical reflex triode was designed and directly driven by a four-stage linear transformer driver to generate high intensity pulsed warm x rays. We developed a numerical model of the cylindrical reflex triode and simulated and studied the experimental electron distribution and the radiation characteristics. The working voltage of the cylindrical reflex triode is 220 kV, and the current is about 600 kA. Under the voltage pulse with a rise time of 100 ns, the electron beam spot is uniform, and the duration of the gap without short circuit reaches 200 ns. The x-ray dose is 385 rad (Si), with an irradiation area of 615 cm2 and a uniformity of less than 2:1. The radiation field distribution is basically consistent with the simulation results. Compared with the two-stage series diode on the Flash-II accelerator, the x-ray conversion efficiency of the cylindrical reflex triode is increased about 1.6 times.

Rapid Enrichment and Detection of Silk Residues from Tombs by Double-Antibody Sandwich ELISA Based on Immunomagnetic Beads.

The extraction and identification of silk residues in tombs is of great significance for studying the distribution and spread of early silk. However, the complex organic matter in the tomb hinders the accurate identification of silk. In this study, a double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) based on immunomagnetic beads (IMBs) was developed for the rapid enrichment and detection of silk residues. The double-antibody sandwich ELISA method established by pairing the IMBs prepared by the silk fibroin monoclonal antibody SF-3 and the silk fibroin monoclonal-labeled antibody bio-SF-1 had the highest detection sensitivity, with a linear detection range of 10 to 104 ng mL-1 and a detection limit of 5.12 ng mL-1. This method was excellent in the extraction and analysis of silk residues from archaeological imprints and soil samples and successfully identified silk residues in samples at the final stage of silk degradation (physical invisible silk). The proteomics analysis results demonstrated the feasibility and practicability of this method.

Effectiveness of bisphosphonates on bone mineral density in osteopenic postmenopausal women: A systematic review and network meta-analysis of randomized controlled trials.

BACKGROUND: Various bisphosphonate agents have been proven to be effective in preventing bone loss and fracture in osteopenic postmenopausal women. This study was designed to compare the effectiveness of various BPs on preventing the loss of bone mineral density (BMD) for postmenopausal women with osteopenia. METHODS: PubMed, EMBASE, and Cochrane Central Register of Controlled Trials were screened up to identify randomized controlled trails comparing effectiveness of BPs or placebo on the BMD of postmenopausal women with osteopenia. Network meta-analysis and standard pair-wise meta-analyses were performed. The main outcomes include the percentage changes of 6-, 12-, 24-, and 36-month BMD at lumbar, total hip and femoral neck, and frequencies of new fractures and severe adverse events. RESULTS: Fourteen randomized controlled trials were eligible, involving 11,540 participants. No significant difference was presented among the available interventions for the 6-month BMD at 3 different sites, but the magnitudes of differences among the treatment regimens became gradually increased along with the extending of follow-up periods. Daily aledronate of more than 5 mg provided the maximal percentage increase on BMD of femoral neck and lumbar spine, while zoledronate provided maximal change on BMD of total hip, at different follow-up periods. This network meta-analysis also demonstrated similar frequencies of new clinical fractures and severe adverse events among different interventions. CONCLUSIONS: A ranking spectrum depicting the effectiveness on BMD percentage change following interventions with different bisphosphonate regimens was provided. Generally, regimens with zoledronate and aledronate were found to be the most effective interventions in the 3 sites at different end points.

Surgical treatment of distal radius giant cell tumors.

We aimed to evaluate the effectiveness of surgical methods commonly used for the clinical treatment of giant cell tumors (GCT) of the distal radius. From 2010 to 2018, 32 patients with GCT of the distal radius who underwent surgical treatment were eligible for the study. Among them, 21 patients with available pathological results, complete imaging data and at least 18 months of follow-up were enrolled in the study. Eleven of the patients underwent en bloc resection and non-vascularized autologous fibula reconstruction (Group A), while 10 patients underwent microwave ablation, lesion curettage, and internal fixation with bone cement (Group B). Imaging was carried out to understand the effect of the surgical treatment and postoperative complications. Variables of interested included operation time and blood loss, preoperative and postoperative wrist joint mobility, and postoperative complications during follow-up. The operation time and intraoperative blood loss in group A were higher than in group B, and the difference between groups was statistically significant. The wrist range of motion before and after surgery was statistically significant both in Group A and Group B (p < 0.05). The scale deviation and MSTS scores of group A were better than group B (p > 0.05), flexion, extension, radial deviation index in group B was better than group A (p < 0.05). By evaluating the postoperative functional outcomes of the operated wrist in the two groups, we found that both surgical methods are reliable for treating GCT of the distal radius, with satisfactory postoperative functional recovery and a low incidence of postoperative recurrence (only 1 of 10 patients in group B). The two surgical methods have their own advantages and disadvantages and provide surgeons with one more choice in the clinical context.

Maternal treatment with agonistic autoantibodies against type-1 angiotensin II receptor in late pregnancy increases apoptosis of myocardial cells and myocardial susceptibility to ischemia-reperfusion injury in offspring rats.

Epidemiological studies have demonstrated that offspring born to mothers preeclampsia (PE) are at increased risk for developing cardiovascular diseases after birth, but the underlying mechanism is unknown. Angiotensin II receptor type 1 autoantibody (AT1-AA), an agonist acting via activation of the AT1 receptor, is believed to be involved in the pathogenesis of both PE and fetal growth restriction. The aim of the present study was to confirm the hypothesis that prenatal AT1-AA exposure increases the heart susceptibility to ischemia/reperfusion injury (IRI) in the offspring in an AT1-AA-induced animal model of PE, and determine whether or not the increase of maternal AT1-AA level is a factor contributing to sustained abnormalities of the heart structure during infancy. The hearts of 45-day-old offspring rats were studied using Langendorff preparation to determine the susceptibility of the heart to IRI. The results showed that the body weight of the maternal rats was not significantly different between the study and control groups, but the body weight of their offspring in AT1-AA group was decreased slightly at day 21 of gestational age, and at day 3 after birth. Although the heart weight index was not significantly affected at all ages examined, AT1-AA significantly increased the size of myocardial cells of the left ventricle (LV) at the age of 45 days. AT1-AA gained access to fetal circulation via the placenta and induced apoptosis of fetal myocardial cells. AT1-AA also significantly delayed recovery from IRI and affected the LV function of 45-day-old offspring. This was associated with a significant increase in IRI-induced LV myocardial infarct size. These results suggest that AT1-AA induced abnormal apoptosis of fetal myocardial cells during the fetal period and increased the cardiac susceptibility to IRI in adult offspring.