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Data-driven prediction of the glass-forming ability of modeled alloys by supervised machine learning
No full textThe ability of a matter to fall into a glassy state upon cooling differs greatly among metallic alloys. It is conventionally measured by the critical cooling rate Rc, below which crystallization inevitably happens. There are a lot of factors involved in determining Rc for an alloy, including both elemental features and alloy properties. However, the underlying physical mechanism is still far from being well understood. Therefore, the design of new metallic glasses is mainly by time- and labor-consuming trial-and-error experiments. This considerably slows down the development process of metallic glasses. Nowadays, large-scale computer simulations have been playing a significant role in understanding glass formation. Although the atomic-scale features can be well captured, the simulations themselves are constrained to a limited timescale. To overcome these issues, we propose to explore the glass-forming ability of the modeled alloys from computer simulations by supervised machine learning. We aim to gain insights into the key features determining Rc and found that the non-linear couplings of the geometrical and energetic factors are of great importance. An optimized machine learning model is then established to predict new glass formers with a timescale beyond the current simulation capability. This study will shed new light on both unveiling the glass formation mechanism and guiding new alloy design in practice
Production of a selective antibacterial fatty acid against Staphylococcus aureus by Bifidobacterium strains
No full textAims: C16 monounsaturated fatty acid (C16:1) show antibacterial activity against Staphylococcus aureus, a pathogen associated with various diseases such as atopic dermatitis and bacteremia, while the compound does not exhibit antibacterial activity against Staphylococcus epidermidis, an epidermal commensal that inhibits the growth of S. aureus. In this study, we aimed to find bifidobacterial strains with the ability to produce C16:1 and to find a practical manner to utilize C16:1-producing strains in industry.Methods: Various Bifidobacterium strains were screened for their content of C16:1. The chemical identity of C16:1 produced by a selected strain was analyzed by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). Medium components that affect the C16:1 content of the selected strain were investigated. Antibacterial activity against staphylococci was compared between the authentic C16:1 isomers and total fatty acids (TFA) extracted from the selected strain.Results: B. adolescentis 12451, B. adolescentis 12-111, B. boum JCM 1211, and Bifidobacterium sp. JCM 7042 showed high C16:1 content among the tested strains. TFA extracted from Bifidobacterium sp. JCM 7042 contained C16:1 at 2.3% as the fatty acid constituent (2.4 mg/L of broth). Through GC-MS and LC-MS analyses, the C16:1 synthesized by Bifidobacterium sp. JCM 7042 was identified as 7-cis-hexadecenoic acid (7-cis-C16:1). The authentic 7-cis-C16:1 showed strong and selective antibacterial activity against S. aureus, similar to 6-cis-C16:1, with a minimum inhibitory concentration (MIC) of < 10 µg/mL. Components that increase C16:1 productivity were not found in the MRS and TOS media; however, Tween 80 was shown to considerably reduce the C16:1 ratio in TFA. Antibacterial activity against S. aureus was observed when the TFA extracted from Bifidobacterium sp. JCM 7042 contained high level of 7-cis-C16:1 (6.1% in TFA) but not when it contained low level of 7-cis-C16:1 (0.1% in TFA).Conclusion: The fatty acid, 7-cis-C16:1, which can selectively inhibit the S. aureus growth, is accumulated in TFA of several bifidobacteria. The TFA extracted from cultured cells of Bifidobacterium sp. JCM 7042 demonstrated antibacterial activity. From a practical viewpoint, our findings are important for developing an efficient method to produce novel skin care cosmetics, functional dairy foods, and other commodities
A rapid assessment method to estimate the prevalence of ectoparasitoses in Brazil: tungiasis and scabies as case studies
No full textThe epidemiologies of the ectoparasitoses tungiasis and scabies are unknown, and their distribution has not been described systematically in Brazil. We developed a rapid assessment method (RAM) based on an online questionnaire as a new tool to assess the prevalence of tungiasis and scabies and severe disease at the municipality level in the state of Ceará in northeast Brazil. As a first step, online records of tungiasis and scabies were collected from scientific publications, lay media, and the gray literature. Then, an image-based RAM with questions about the prevalence of these diseases, severe diseases, and animal reservoirs was developed as an online open questionnaire. Valid responses were obtained from 1265 respondents, primarily health professionals, from all 184 municipalities in the state. The literature review returned results for only two municipalities. The number of responses from the online questionnaires differed considerably between municipalities (one to 104 responses/municipality). Active contact with municipality health secretariats increased the number of respondents, especially community health agents. The RAM obtained consistent results regarding the prevalence and other epidemiological information. Our approach rapidly obtained primary data on the occurrence of these two important but neglected ectoparasitoses at the municipality level without considerable cost. This approach provides information for planning evidence-based control measures and identifying high-risk areas for focused studies. The RAM can easily be adapted and extended to other settings, countries, and diseases
Organic-inorganic hybrid quasi-2D perovskites incorporated with fluorinated additives for efficient and stable four-terminal tandem solar cells
No full textQuasi-two-dimensional (2D) lead halide perovskites have emerged as promising candidates for improving the environmental stability of perovskite solar cells (PSCs). Herein, we report the preparation of a new quasi-2D perovskite by introducing a fluorine-containing additive [3-(trifluoromethyl)benzylammonium iodide (3-TFMBAI)] into Cs0.17FA0.83Pb(I0.83Br0.17)3. The moderate doping of 3-TFMBAI effectively induces the formation of the Ruddlesden-Popper perovskite phase, which can passivate the trap states and restrain the ionic motion in the perovskite lattice. The constructed 3-(trifluoromethyl)benzylamine molecular planes with strong hydrophobicity favorably suppress the decomposition and collapse of the perovskite phase against humidity. Moreover, the introduction of Cs+ and Br- ions tune the bandgap and improve the absorption, crystallinity and thermal stability of the perovskite films. As a result, a champion photoelectric conversion efficiency (PCE) of 20.89% is achieved, along with an improved open-circuit voltage reaching 1.22 V. The quasi-2D PSCs without encapsulation maintain 90.7% of the initial PCE after 1000 h under continuous heating at 60 °C and simultaneous exposure to humid air with a relative humidity of 60%. Four-terminal tandem solar cells are fabricated by combining top semi-transparent quasi-2D PSCs with bottom monocrystalline silicon solar cells, achieving an overall PCE of 23.53% and favorable performance stability
Modulation of photogenerated holes for enhanced photoelectrocatalytic performance
No full textUtilizing clean energy derived from photoelectrocatalytic reactions is expected to be an excellent choice to fundamentally solve the problem of the human energy crisis. Photoelectrochemical (PEC) cell can effectively promote charge separation and improve solar energy conversion efficiency since it combines the advantages of photocatalysis and electrocatalysis. However, the hole transfer and subsequent oxidation reaction in the PEC process are slow, resulting in the rapid recombination of photogenerated electron-hole pairs and low PEC performance. The half-oxidation reaction involving photogenerated holes is the bottleneck of PEC water splitting. Therefore, hole modulation has been an important research area in the field of catalysis. However, compared with electron modulation, research on hole modulation is limited and still faces great challenges. It is therefore of great significance to develop effective modulation strategies for photogenerated holes. This review summarizes the hole modulation strategies developed in the last five years, including hole sacrificial agents, nanostructural modification, heterostructure construction and cocatalyst modification. Hole modulation dynamics studies, such as transient absorption spectroscopy, time-resolved photoluminescence spectroscopy, transient photovoltage and scanning electrochemical microscopy, are also summarized. Moreover, relevant conclusions and an outlook are proposed
Factors affecting the levels and pathways of atmospheric brominated flame retardant uptake by humans in different weather conditions
No full textThe health risks posed by atmospheric brominated flame retardants (BFRs) have been widely studied, but there remains a lack of clarity about exposure differences between clear days and haze days. We sampled the total suspended particle (TSP) and gaseous BFRs on clear days in summer, clear days in winter, and haze days in winter in Harbin, China, to investigate the variations in the concentrations and intakes (dermal and inhalation) in the different weather conditions. The concentrations of atmospheric BFRs were highest on haze days in winter (185 pg/m3), followed by clear days in summer (158 pg/m3), and clear days in winter (79.2 pg/m3), and these concentrations were significantly correlated with the concentrations of TSP. The human intake in the different weather conditions followed the pattern of the BFR concentrations, and the human intake of atmospheric BFRs was dominated by inhalation. A comparison of the BFR levels showed that the human intake of gaseous and particulate BFRs varied in the three weather conditions and that the inhalation intake, but not the dermal intake, was influenced under high concentrations of gaseous BFRs with low molecular weight
An analysis of the role of targeted muscle reinnervation (TMR) in quality of life and pain outcomes: a case series
No full textAim: Targeted muscle reinnervation (TMR) surgery has fundamentally changed the management of patients who have suffered or are about to undergo amputation. Providing nerve stumps with a muscle target has been shown to have profound effects on levels of post-amputation pain in relation to phantom limb pain (PLP) and neuroma pain (NP). The primary objective of this report was to quantify pain parameters for this population and to measure the impact on health-related quality of life (HRQol) before and after TMR surgery. In this case series, we evaluate the role of TMR in addressing both pain and the impact of the surgery on the patient’s quality of life.Methods: A retrospective analysis of 15 upper limb amputee patients who underwent TMR by the Relimb Unit in London, UK. Participants’ perceptions of pain were determined using the 11-point numerical (Pain) rating scale (NRS) and HRQoL was calculated using the Euroqol EQ-5D-5L questionnaire at two time points, comparing both pain and perceived quality of life pre and post surgery. The Wilcoxon Signed Rank Test was used for the NRS data and a paired sample t-test was used for the EQ-VAS data.Results: A total of 15 patients completed the evaluation. We observed statistically significant reductions in both PLP (pre-operative mean: 7.6, post-operative mean: 2.7, P < 0.05) and NP (pre-operative mean: 6.4, post-operative mean: 2.5, P < 0.05) in these patients. Similarly, HRQoL observed on the EQ-VAS scale demonstrated a significant improvement in quality of life, from 68 pre-operatively to 78 post-procedure (P < 0.05).Conclusion: This is the first quantified evaluation of changes in HRQoL after TMR surgery for upper limb amputation. There appears to be a significant improvement in both HRQoL and overall perception of pain. This finding may have important implications for funding and national resource allocation for TMR surgery
Minimally invasive spleen-preserving distal pancreatectomy: real-world data from the Italian National Registry of Minimally Invasive Pancreatic Surgery (IGoMIPS)
No full textAim: Minimally invasive distal pancreatectomy has become the standard of care for benign and low malignant lesions. Spleen preservation in this setting has been proposed to reduce surgical trauma and long-term sequelae. The aim of the current study is to present real-world data on indications, techniques, and outcomes of spleen-preserving distal pancreatectomy (SPDP).Methods: Patients who underwent SPDP and distal pancreatectomy with splenectomy (DPWS) were extracted from the 2019-2022 Italian National Registry for Minimally Invasive Pancreatic Surgery (IGoMIPS). Perioperative and pathological data were collected. Results: One hundred and ten patients underwent SPDP and five hundred and seventy-eight underwent DPWS. Patients undergoing SPDP were significantly younger (56 vs. 63.5 years; P < 0.001). Seventy-six percent of SPDP cases were performed in six out of thirty-four IGoMIPS centers. SPDP was performed predominantly for Neuroendocrine Tumors (43.6% vs.23.5%; P < 0.001) and for smaller lesions (T1 57.6% vs. 29.8%; P < 0.001). The conversion rate was higher in the case of DPWS (7.6% vs. 0.9%; P = 0.006), even when pancreatic cancer was ruled out (5.0% vs. 0.9%; P = 0.045). The robotic approach was most commonly used for SPDP (50.9% vs. 29.7%; P < 0.001). No difference in postoperative outcomes and length of stay was observed between the two groups, as well as between robotic and laparoscopic approaches in the SPDP group. A trend toward a lower rate of postoperative sepsis was observed after SPDP (0.9% vs. 5.2%; P = 0.056). In 84.7% of SPDP, splenic vessels were preserved (Kimura procedure) without an impact on short-term postoperative outcomes. Conclusion: In this registry analysis, SPDP was feasible and safe. The Kimura procedure was prevalent over the Warshaw procedure. The typical patient undergoing SPDP was young with a neuroendocrine tumor at an early stage. Robotic assistance was used more frequently for SPDP than for DPWS
Extracellular vesicles from the CNS play pivotal roles in neuroprotection and neurodegeneration: lessons from in vitro experiments
No full textIntercellular communication between diverse cell types is crucial for the maintenance of the central nervous system, and exosomes have been shown to play an important role in this process. Exosomes are small extracellular vesicles (EVs) that are released by all cell types and carry cargoes that can elicit downstream effects in recipient cells. Exosomal communication in the central nervous system has been implicated in many neurodegenerative diseases, ranging from Alzheimer’s disease to major depressive disorder. Though there remain many unknowns in the field of EV biology, in vitro experiments can provide many insights into their potential roles in health and disease. In this review, we discuss the findings of many in vitro EV experiments, with a focus on the potential roles in regulating cell viability, inflammation, oxidative stress, and neurite integrity in the central nervous system
Non-emergency responses in the 311 system during the early stage of the COVID-19 pandemic: a case study of Kansas city
No full textIn response to the COVID-19 pandemic, many U.S. citizens sought information and support from their city governance through the 311 non-emergency service request system. The main purpose of this study was to analyze the temporal trends in the 311 data before and during the first few months of the COVID-19 pandemic (3/1/2019 to 9/1/2020). Like other major U.S. cities such as Dallas and New York City, analysis of Kansas City 311 data showed that the COVID-19 pandemic has led to a considerable decline in the aggregate number of calls. However, five service categories (“Public Safety”, “Public Health”, “Trash/Recycling”, “Parks & Recreation”, and “Property/Buildings/Construction”) experienced a substantial increase in call volume. To explore whether these changes are driven by COVID-related service requests, we used the description text data and identified 2,379 requests related to the pandemic, accounting for 4.3% of all non-emergency requests in Kansas City between March and August 2020. More than half of the COVID-related requests reported mask violations, where people failed to wear masks or did not wear masks properly. Compared to the non-COVID-related requests, citizens were more likely to seek non-emergency services through phone and email and less likely to use the web as means of communication. In addition, most changes in “Public Safety” and “Public Health” request volumes were driven by these COVID-related requests. These results can help city officials and decision makers improve the city’s resilience by allocating resources for the abovementioned five service categories during a pandemic. In conclusion, early-stage analysis of open-access 311 data can be a catalyst for local governments to quickly and properly respond and build long-term resilience against future pandemics and other health threats
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