Optimization of extended Kozak elements enhances recombinant proteins expression in CHO cells.

In eukaryotes, the localization of small ribosomal subunits to mRNA transcripts requires the translation of Kozak elements at the starting site. The sequence of Kozak elements affects the translation efficiency of protein synthesis. However, whether the upstream nucleotide of Kozak sequence affects the expression of recombinant proteins in Chinese hamster ovary (CHO) cells remains unclear. In order to find the optimal sequence to enhance recombinant proteins expression in CHO cells, -10 to +4 sequences around ATG in 100 CHO genes were compared, and the extended Kozak elements with different translation intensities were constructed. Using the classic Kozak element as control, the effects of optimized extended Kozak elements on the secreted alkaline phosphatase (SEAP) and human serum albumin (HSA) gene were studied. The results showed that the optimized extended Kozak sequence can enhance the stable expression level of recombinant proteins in CHO cells. Furthermore, it was found that the increased expression level of the recombinant protein was not related with higher transcription level. In summary, optimizing extended Kozak elements can enhance the expression of recombinant proteins in CHO cells, which contributes to the construction of an efficient expression system for CHO cells.

Exploring the microRNA-mRNA regulatory network associated with solasonine in bladder cancer.

Background: Solasonine has been demonstrated to exert an inhibitory effect on bladder cancer (BC), but the potential mechanisms remain unclear. Therefore, the aim of this study is to explore the association between microRNAs (miRNAs)-mediated regulation and the anti-tumor activities of solasonine in BC. Methods: MiRNA sequencing was performed to identify the differentially expressed microRNAs (DE-miRNAs) associated with solasonine in BC cells. Functional enrichment analyses of the DE-miRNAs activated and inhibited by solasonine were then conducted. The DE-miRNAs with prognostic value for BC and those differentially expressed in the BC samples were subsequently identified as the hub DE-miRNAs. After identifying the messenger RNAs (mRNAs) that were targeted by the hub DE-miRNAs and those differentially expressed in the BC samples, a protein-protein interaction analysis was performed to identify the core downstream genes, which were then used to construct a solasonine-miRNA-mRNA regulatory network. Results: A total of 27 activated and 19 inhibited solasonine-mediated DE-miRNAs were identified that were found to be associated with several tumor-related biological functions and pathways. After integrating the results of the survival analysis and expression assessment, the following nine hub DE-miRNAs were identified: hsa-miR-127-3p, hsa-miR-450b-5p, hsa-miR-99a-5p, hsa-miR-197-3p, hsa-miR-423-3p, hsa-miR-4326, hsa-miR-625-3p, hsa-miR-625-5p, and hsa-miR-92a-3p. The DE-mRNAs targeted by the hub DE-miRNAs were predicted, and 30 core downstream genes were used to construct the solasonine-miRNA-mRNA regulatory network. miR-450b-5p was shown to be associated with the most mRNAs in this network, which suggests that it plays a crucial role in the solasonine-mediated anti-BC effect. Conclusions: A regulatory network, including solasonine, miRNAs, and mRNAs related to BC, was constructed. This network provides extensive insights into the molecular regulatory mechanisms that underlie the anti-cancer efficacy of solasonine in BC.

Diffuse hyperpigmentation with guttate hypopigmentation: a new pigmentary disorder.

Diffuse hyperpigmentation with guttate hypopigmentation (DHGH) is a new acquired pigmentary disorder. Only a few cases have previously been reported in the Chinese population, in Chinese. To summarise the clinical, dermoscopic, and histopathological findings of DHGH in the English literature, to improve the recognition and management of this condition. This was a retrospective study to summarise the clinical, dermoscopic, and pathological findings of nine cases of DHGH. All nine patients with DHGH were female. The age at onset varied from 6 to 24 years (median 17 years). Patients were generally in good health without systemic disease. The lesions were often generalised to the trunk and extremities without any discomfort. Typical lesions were characterised by multiple uniform hypopigmented spots, 2-5 mm in diameter, irregularly distributed over diffuse hyperpigmentation. Dermoscopy revealed multiple blurred patchy areas of brownish pigmentation, sparse linear and dotted vessels, and perifollicular pigmentation on a white to bright white background, surrounded by brown hyperpigmentation. Histopathological findings included mild abnormal pigment of the epidermis, focal vacuolar degeneration of the basal cells, mild pigment incontinence and perivascular lymphocytic infiltration in the dermis. DHGH is a new entity with distinctive clinical manifestations that differ from those of other known pigmentary disorders. So far, DHGH has only been reported in the Chinese population. It may not be uncommon and has not received much attention due to the few reports. The aetiology and pathogenesis of DHGH are still unknown and require further investigation.

Preliminary outcomes of endovascular treatment of moyamoya disease.

PURPOSE: This study aimed to investigate the effectiveness and safety of endovascular revascularisation of intracranial artery occlusion and stenosis in moyamoya disease using stent angioplasty. MATERIALS AND METHODS: We recruited 12 patients (8 women and 4 men) with occlusion and stenosis of intracranial arteries in the context of moyamoya disease who underwent endovascular stent angioplasty. Clinical data, baseline conditions, lesion location, treatment outcomes, periprocedural complications, and follow-up outcomes were analysed. RESULTS: The occlusion was located at the M1 segment of the middle cerebral artery in 8 patients, at both the M1 and A2 segments in one patient, and at the C7 segment of the internal carotid artery in 3. Thirteen stents were deployed at the occlusion site, including the low-profile visualized intraluminal support (LVIS) device in 8 patients, an LVIS device and a Solitaire AB stent in one, and a Leo stent in 3, with a success rate of 100% and no intraprocedural complications. Plain CT imaging after stenting revealed leakage of contrast agent, which disappeared on the second day, resulting in no clinical symptoms or neurological sequelae. Follow-up angiography studies were performed in all patients for 6-12 months (mean, 8.8). Slight asymptomatic in-stent stenosis was observed in 2 patients (16.7%), and no neurological deficits were observed in the other patients. All preoperative ischaemic symptoms completely disappeared at follow-up. CONCLUSION: Stent angioplasty is a safe and effective treatment for occlusion and stenosis of intracranial arteries in moyamoya disease.

A novel tRNA-derived fragment tRF-17-18VBY9M works as a potential diagnostic biomarker for gastric cancer.

BACKGROUND: Gastric cancer (GC) is one of the most prevalent malignant tumors worldwide. The low effectiveness of common biomarkers for the detection of early GC makes it essential to seek new biomarkers to improve diagnostic efficacy. tsRNAs (transfer RNA-derived small RNAs) are related to the growth of malignant tumors. In this article, we focused on whether tsRNAs may be employed as biomarkers for GC. METHODS: tRF-17-18VBY9M was screened in the tsRFun database as a research object. The methodological efficacy of tRF-17-18VBY9M was evaluated using Sanger sequencing, agarose gel electrophoresis assays, and gradient dilution. The χ2 test was applied to assess the interaction between tRF-17-18VBY9M expression and clinicopathologic characteristics. The receiver operating characteristic (ROC) curve was utilized to investigate the clinical efficiency of tRF-17-18VBY9M in GC. RESULTS: The Chi-square test demonstrated that high-expressed tRF-17-18VBY9M was closely associated with the T stage, tumor node metastasis stage (TNM), lymph node metastasis, and neurological/vascular invasion. ROC curve analysis revealed that the diagnostic value of tRF-17-18VBY9M in GC was superior to carcinoembryonic antigen (CEA), carbohydrate antigen 199 (CA199), and carbohydrate antigen 724 (CA724). CONCLUSION: tRF-17-18VBY9M is up-regulated in both GC sera and tissues. Differential tRF-17-18VBY9M expression distinguishes GC patients from healthy donors and gastritis patients, which suggests tRF-17-18VBY9M could act as a diagnostic biomarker in GC.

Magnetic Seeding of SPIO-BMSCs Into a Biphasic Scaffold Can Promote Tendon-Bone Healing After Rotator Cuff Repair.

BACKGROUND: The tendon-bone interface (TBI) in the rotator cuff has a poor intrinsic capacity for healing, which increases the risk of retear after rotator cuff repair (RCR). However, facilitating regeneration of the TBI still remains a great clinical challenge. Herein, the authors established a novel strategy based on magnetic seeding to enhance the TBI regeneration. HYPOTHESIS: Magnetic seeding bone marrow mesenchymal stem cells labeled with superparamagnetic iron oxide (SPIO-BMSCs) into a biphasic scaffold can promote tendon-bone healing after RCR. STUDY DESIGN: Controlled laboratory study. METHODS: BMSCs were labeled with SPIOs. Prussian blue staining, CCK-8 tests, Western blot, and quantitative reverse transcription polymerase chain reaction (PCR) were used to determine the optimal effect concentration of SPIOs on cell bioactivities and abilities. Then SPIO-BMSCs were magnetically seeded into a biphasic scaffold under a magnetic field. The seeding efficacy was assessed by a scanning electron microscope, and the potential mechanism in chondrogenic differentiation after seeding SPIO-BMSCs into the scaffold was evaluated by Western blot and PCR. Furthermore, the effect of SPIO-BMSC/biphasic scaffold on tendon-bone healing after RCR using a rat model was examined using histological analysis, enzyme-linked immunosorbent assay, and biomechanical evaluation. RESULTS: BMSCs labeled with 100 µg/mL SPIO had no effect on cell bioactivities and the ability of chondrogenic differentiation. SPIO-BMSCs were magnetically seeded into a biphasic scaffold, which offered a high seeding efficacy to enhance chondrogenic differentiation of SPIO-BMSCs via the CDR1as/miR-7/FGF2 pathway for TBI formation in vitro. Furthermore, in vivo application of the biphasic scaffold with magnetically seeded SPIO-BMSCs showed their regenerative potential, indicating that they could significantly accelerate and promote TBI healing with superior biomechanical properties after RCR in a rat rotator cuff tear model. CONCLUSION: Magnetically seeding SPIO-BMSCs into a biphasic scaffold enhanced seeding efficacy to promote cell distribution and condensation. This construct enhanced the chondrogenesis process via the CDR1as/miR-7/FGF2 pathway and further promoted tendon-bone healing after RCR in a rat rotator cuff tear model. CLINICAL RELEVANCE: This study provides an alternative strategy for improving TBI healing after RCR.

Human circular RNA hsa_circ_0000231 clinical diagnostic effectiveness as a new tumor marker in gastric cancer.

BACKGROUND: Owing to the subtlety of initial symptoms associated with gastric cancer (GC), the majority of patients are diagnosed at later stages. Given the absence of reliable diagnostic markers, it is imperative to identify novel markers that exhibit high sensitivity and specificity. Circular RNA, a non-coding RNA, plays an important role in tumorigenesis and development and is well expressed in body fluids. AIMS: In this study, we aimed to identify hsa_circ_0000231 as a new biomarker for the diagnosis of GC and to assess its clinical diagnostic value in serum. METHODS AND RESULTS: The stability and correctness of hsa_circ_0000231 was determined by agarose gel electrophoresis, Rnase R assay and Sanger sequencing. Real-time quantitative polymerase chain reaction (qRT-PCR) was designed to discover the expression level of hsa_circ_0000231 and whether it has dynamic serum monitoring capability. The correlation between hsa_circ_0000231 and clinicopathological parameters was analyzed by collecting clinical and pathological data from GC patients. In addition, diagnostic efficacy was assessed by constructing receiver operating characteristic curves (ROC). Hsa_circ_0000231 exhibits a stable and consistently expressed structure. In GC serum, cells, and tissues, it demonstrates reduced expression levels. Elevated expression levels observed postoperatively suggest its potential for dynamic monitoring. Additionally its expression level correlates with TNM staging and neuro/vascular differentiation. The area under ROC curve (AUC) for hsa_circ_0000231 is 0.781, indicating its superior diagnostic value compared to CEA, CA19-9, and CA72-4. The combination of these four indicators enhances diagnostic accuracy, with an AUC of 0.833. CONCLUSIONS: The stable expression of hsa_circ_0000231 in the serum of gastric cancer patients holds promise as a novel biomarker for both the diagnosis and dynamic monitoring of GC.

Structure-Activity Relationship Study of (E)-3-(6-Fluoro-1H-indol-3-Yl)-2-methyl-1-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (FC116) Against Metastatic Colorectal Cancers Resistant to Oxaliplatin.

Advanced metastatic colorectal cancer (mCRC) and the development of drug resistance to chemotherapy pose significant challenges in clinical settings. In previous studies, we have demonstrated the potent cytotoxic activity of (E)-3-(6-fluoro-1H-indol-3-yl)-2-methyl-1-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (FC116) and related 30 derivatives against mCRC by targeting microtubules. In this study, we aimed to evaluate the efficacy of the 31 compounds and explore the structure-activity relationship (SAR) against oxaliplatin-resistant mCRC. We found that most of the derivatives showed high sensitivity toward the oxaliplatin-resistant HCT-116/L cells. Particularly, FC116 exhibited a better GI50 value against the resistant mCRC cell line, HCT-116/L, compared to standard therapies. We also observed a safer therapeutic window for FC116 and a synergistic effect when it was used in combination with oxaliplatin. Mechanistically, FC116 induced the G2/M phase arrest by downregulating cyclin B1 expression through its interaction with microtubules in resistant colorectal cancer cells. Furthermore, in vivo experiments demonstrated that FC116 significantly suppressed tumor growth, achieving a 78% reduction at a dose of 3 mg/kg, which was superior to the 40% reduction achieved by oxaliplatin treatment. Overall, our findings suggest that the indole-chalcone compound FC116 represents a promising lead for chemotherapy in oxaliplatin-resistant mCRC.

Transfer RNA­derived small RNAs: A class of potential biomarkers in multiple cancers (Review).

Transfer (t)RNA-derived small RNAs (tsRNAs) are a class of novel non-coding small RNAs that are created via precise cleavage of tRNAs or tRNA precursors by different enzymes. tsRNAs are specific biological molecules that serve essential roles in cell proliferation, apoptosis, transcriptional regulation, post-transcriptional modification and translational regulation. Additionally, tsRNAs participate in the pathogenesis of several diseases, particularly in the development of malignant tumors. At present, the process of discovering and understanding the functions of tsRNAs is still in its early stages. The present review introduces the known biological functions and mechanisms of tsRNAs, and discusses the tsRNAs progression in several types of cancers as well as the possibility of tsRNAs becoming novel tumor biomarkers. Furthermore, tsRNAs may promote and hinder tumor formation according to different mechanisms and act as oncogenic or oncostatic molecules. Therefore, tsRNAs may be future potential tumor biomarkers or therapeutic targets.

Clinical characteristics and molecular mechanisms underlying bladder cancer in individuals with spinal cord injury: a systematic review.

BACKGROUND: Patients with spinal cord injury have a relatively high risk for bladder cancer and often complicated with bladder cancer in advanced stages, and the degree of aggressiveness of malignancy is high. Most of the literature is based on disease clinical features while, our study reviews the clinical characteristics and molecular mechanisms of spinal cord injury patients with bladder cancer, so that it might help clinicians better recognize and manage these patients. METHOD: We searched PubMed, Web of Science and Embase, using retrieval type like ("Neurogenic Lower Urinary Tract Dysfunction" OR "Spinal cord injury" OR "Spinal Cord Trauma") AND ("bladder cancer" OR "bladder neoplasm" OR "bladder carcinoma" OR "Urinary Bladder Neoplasms" OR "Bladder Tumor"). In Web of Science, the retrieval type was searched as "Topic", and in PubMed and Embase, as "All Field". The methodological quality of eligible studies and their risk of bias were assessed using the Newcastle-Ottawa scale. This article is registered in PROSPERO with the CBD number: CRD42024508514. RESULT: In WOS, we searched 219 related papers, in PubMed, 122 and in Embase, 363. Thus, a total of 254 articles were included after passing the screening, within a time range between 1960 and 2023. A comprehensive analysis of the data showed that the mortality and incidence rates of bladder cancer in spinal cord injury patients were higher than that of the general population, and the most frequent pathological type was squamous cell carcinoma. In parallel to long-term urinary tract infection and indwelling catheterization, the role of molecules such as NO, MiR 1949 and Rb 1. was found to be crucial pathogenetically. CONCLUSION: This review highlights the risk of bladder cancer in SCI patients, comprehensively addressing the clinical characteristics and related molecular mechanisms. However, given that there are few studies on the molecular mechanisms of bladder cancer in spinal cord injury, further research is needed to expand the understanding of the disease.

Hsa_Circ_0002762 may be a New Marker for the Gastric Cancer Diagnosis and Prognosis.

BACKGROUND: The global incidence and mortality rate of gastric carcinoma (GC) persists at elevated levels, often manifesting no overt symptoms in its early stages. Hsa_circ_0002762 has been identified as an important modulator in cervical cancer. This study aims to explore its role in the context of GC. METHODS: A quantitative real-time polymerase chain reaction (qPCR) was implemented to assess the expression level of hsa_circ_0002762. The over-expression was confirmed through an examination of 28 cases of gastric cancer and their corresponding adjacent tissues. In addition, plasma samples from 78 healthy individuals, from 45 benign gastritis patients, and from 106 gastric cancer patients were collected, and the diagnostic efficacy was assessed by analyzing the receiver operating characteristic (ROC) curve. Simultaneously, postoperative specimens from 36 GC cases were collected, and a Kaplan-Meier survival analysis curve was used to evaluate the prognosis of GC. RESULTS: The study revealed an up-regulation in the expression of hsa_circ_0002762 in gastric cancer plasma and tissues. The area under the receiver operating characteristic (ROC) curve for serum hsa_circ_0002762 was 0.784 (95% CI: 0.719 - 0.851), indicating a higher diagnostic efficiency compared to CEA (0.687, 95% CI: 0.611 - 0.763) and CA199 (0.699, 95% CI: 0.625 - 0.744). Combining these three biomarkers demonstrated an increased sensitivity in the diagnostic effectiveness. Finally, postoperative dynamic monitoring revealed a practical utility in predicting the clinical prognosis using serum has_circ_0002762. CONCLUSIONS: The findings from our study suggest that hsa_circ_0002762 holds promise as a novel diagnostic and prognostic marker for individuals with GC.

Unveiling the Dynamic Electrocatalytic Activity of Online Synthesized Bimetallic Nanocatalysts via Electrochemiluminescence Microscopy.

Effective bimetallic nanoelectrocatalysis demands precise control of composition, structure, and understanding catalytic mechanisms. To address these challenges, we employ a two-in-one approach, integrating online synthesis with real-time imaging of bimetallic Au@Metal core-shell nanoparticles (Au@M NPs) via electrochemiluminescence microscopy (ECLM). Within 120 s, online electrodeposition and in situ catalytic activity screening alternate. ECLM captures transient faradaic processes during potential switches, visualizes electrochemical processes in real-time, and tracks catalytic activity dynamics at the single-particle level. Analysis using ECL photon flux density eliminates size effects and yields quantitative electrocatalytic activity results. Notably, a nonlinear activity trend corresponding to the shell metal to Au surface atomic ratio is discerned, quantifying the optimal surface component ratio of Au@M NPs. This approach offers a comprehensive understanding of catalytic behavior during the deposition process with high spatiotemporal resolution, which is crucial for tailoring efficient bimetallic nanocatalysts for diverse applications.

Is It Appropriate to Adjust the Uric Acid Reference Interval?

BACKGROUND: This study aims to explore the observable distribution of serum uric acid levels in healthy adults residing in China's coastal areas and to assess the suitability of current reference intervals. METHODS: The study incorporated 20,786 participants. The overall uric acid level displayed a skewed distribution, leading to the division of subjects into six groups based on gender and age. The analysis was conducted to comprehend the distribution of UA in various groups and seasons, establish and validate the reference intervals for the surface healthy population in this region, and analyze the abnormality rates using different reference intervals. RESULTS: Statistically significant differences were observed between the uric acid levels of males and females across all age groups (ALL p < 0.05). Furthermore, there were statistical differences in uric acid levels among different age groups for both genders (H = 69.593 and 326.348, all p < 0.001). The overall reference interval was determined as 238 - 488 µmol/L for males and 155 - 364 µmol/L for females, based on the 95% confidence interval (P2.5 - P97.5). The established reference intervals, grounded on gender and age group, were validated, showing statistically significant disparities in UA levels among groups. The abnormality rate in males decreased by 56.90% following the adjustment of the reference interval. CONCLUSIONS: The study revealed that UA levels at all ages exhibited varying degrees of "right shift". Additionally, the low-value population should not be overlooked in the clinical evaluation of UA test results. Setting a reasonable reference interval and clinical decision level is crucial for clinical diagnosis and treatment.

Research Advances in Stem Cell Therapy for Erectile Dysfunction.

Erectile dysfunction (ED) is a common clinical condition that mainly affects men aged over 40 years. Various causes contribute to the progression of ED, including pelvic nerve injury, diabetes, metabolic syndrome, age, Peyronie's disease, smoking, and psychological disorders. Current treatments for ED are limited to symptom relief and do not address the root cause. Stem cells, with their powerful ability to proliferate and differentiate, are a promising approach for the treatment of male ED and are gradually gaining widespread attention. Current uses for treating ED have been studied primarily in experimental animals, with most studies observing improvements in erectile quality as well as improvements in erectile tissue. However, research on stem cell therapy for human ED is still limited. This article summarizes the recent literature on basic stem cell research on ED, including cavernous nerve injury, aging, diabetes, and sclerosing penile disease, and describes mechanisms of action and therapeutic effects of various stem cell therapies in experimental animals. Stem cells are also believed to interact with host tissue in a paracrine manner, and improved function can be supported through both implantation and paracrine factors. To date, stem cells have shown some preliminary promising results in animal and human models of ED.

An efficient peptide ligase engineered from a bamboo asparaginyl endopeptidase.

In recent years, a few asparaginyl endopeptidases (AEPs) from certain higher plants have been identified as efficient peptide ligases with wide applications in protein labeling and cyclic peptide synthesis. Recently, we developed a NanoLuc Binary Technology (NanoBiT)-based peptide ligase activity assay to identify more AEP-type peptide ligases. Herein, we screened 61 bamboo species from 16 genera using this assay and detected AEP-type peptide ligase activity in the crude extract of all tested bamboo leaves. From a popular bamboo species, Bambusa multiplex, we identified a full-length AEP-type peptide ligase candidate (BmAEP1) via transcriptomic sequencing. After its zymogen was overexpressed in Escherichia coli and self-activated in vitro, BmAEP1 displayed high peptide ligase activity, but with considerable hydrolytic activity. After site-directed mutagenesis of its ligase activity determinants, the mutant zymogen of [G238V]BmAEP1 was normally overexpressed in E. coli, but failed to activate itself. To resolve this problem, we developed a novel protease-assisted activation approach in which trypsin was used to cleave the mutant zymogen and was then conveniently removed via ion-exchange chromatography. After the noncovalently bound cap domain was dissociated from the catalytic core domain under acidic conditions, the recombinant [G238V]BmAEP1 displayed high peptide ligase activity with much lower hydrolytic activity and could efficiently catalyze inter-molecular protein ligation and intramolecular peptide cyclization. Thus, the engineered bamboo-derived peptide ligase represents a novel tool for protein labeling and cyclic peptide synthesis.

Nursing Care of a Child With Delirium Receiving Venoarterial Extracorporeal Membrane Oxygenation: A Case Report.

INTRODUCTION: Children receiving extracorporeal membrane oxygenation are prone to delirium. This case report describes the nursing care of a child with delirium who received venoarterial extracorporeal membrane oxygenation. Relevant interventions and precautions are also discussed. CLINICAL FINDINGS: A 6-year-old girl was admitted to the pediatric intensive care unit with a 2-day history of vomiting and fever. The child underwent cannulation for venoarterial extracorporeal membrane oxygenation. DIAGNOSIS: The child was diagnosed with acute fulminant myocarditis, cardiac shock, and ventricular arrhythmia. INTERVENTIONS: On the third day of extracorporeal membrane oxygenation, bedside nurses began using the Cornell Assessment of Pediatric Delirium to assess the child for delirium symptoms. The team of physicians and nurses incorporated a nonpharmacologic delirium management bundle into pediatric daily care. Delirium screening, analgesia and sedation management, sleep promotion, and family participation were implemented. OUTCOMES: During the 18 days of pediatric intensive care unit hospitalization, the child had 6 days of delirium: 1.5 days of hypoactive delirium, 1.5 days of hyperactive delirium, and 3 days of mixed delirium. The child was successfully discharged home on hospital day 22. CONCLUSION: Caring for a child with delirium receiving venoarterial extracorporeal membrane oxygenation required multidimensional nursing capabilities to prevent and reduce delirium while ensuring safe extracorporeal membrane oxygenation. This report may assist critical care nurses caring for children under similar circumstances.

Machine-learning-assisted and real-time-feedback-controlled growth of InAs/GaAs quantum dots.

The applications of self-assembled InAs/GaAs quantum dots (QDs) for lasers and single photon sources strongly rely on their density and quality. Establishing the process parameters in molecular beam epitaxy (MBE) for a specific density of QDs is a multidimensional optimization challenge, usually addressed through time-consuming and iterative trial-and-error. Here, we report a real-time feedback control method to realize the growth of QDs with arbitrary density, which is fully automated and intelligent. We develop a machine learning (ML) model named 3D ResNet 50 trained using reflection high-energy electron diffraction (RHEED) videos as input instead of static images and providing real-time feedback on surface morphologies for process control. As a result, we demonstrate that ML from previous growth could predict the post-growth density of QDs, by successfully tuning the QD densities in near-real time from 1.5 × 1010 cm-2 down to 3.8 × 108 cm-2 or up to 1.4 × 1011 cm-2. Compared to traditional methods, our approach can dramatically expedite the optimization process and improve the reproducibility of MBE. The concepts and methodologies proved feasible in this work are promising to be applied to a variety of material growth processes, which will revolutionize semiconductor manufacturing for optoelectronic and microelectronic industries.

Association between BMI and osteoporotic fractures at different sites in Chinese women: a case-control retrospective study in Changsha.

BACKGROUND: Osteoporotic fractures are a growing problem in an aging society. The association between body mass index (BMI) and osteoporotic fractures varies by fracture site and ethnicity. Limited knowledge exists regarding this association in native Chinese, particularly utilizing local databases as reference sources. OBJECTIVE: To investigate the association between BMI and osteoporotic fractures at different sites in Chinese women. METHODS: Three thousand ninety-eight female patients with radiographic fractures and 3098 age- and sex-matched healthy controls without fractures were included in the study. Both of them underwent assessment using dual-energy X-ray absorptiometry (DXA), with BMD measurements calculated using our own BMD reference database. Participants were classified into underweight (BMI < 18.5 kg/m2), normal weight (18.5 ≤ BMI < 24.0 kg/m2), overweight (24 ≤ BMI < 28 kg/m2) and obese (BMI ≥ 28 kg/m2) according to the Chinese BMI classification standard. RESULTS: There were 2296 (74.1%) vertebral fractures, 374 (12.1%) femoral neck fractures, and 428 (13.8%) other types of fractures in the case group. Bone mineral density (BMD) was almost lower in the fracture groups compared to the control groups (p = 0.048 to < 0.001). Compared with normal weight, underweight had a protective effect on total [odds ratio (OR) = 0.61; 95% confidence interval (CI), 0.49 -0.75; P< 0.001], and lumbar fractures (OR = 0.52; 95% CI, 0.41 - 0.67; P < 0.001), while obesity was associated with an increased risk for total (OR = 2.26; 95% CI, 1.85 - 2.76; P < 0.001), lumbar (OR = 2.17; 95% CI, 1.72 - 2.73; P < 0.001), and femoral neck fractures (OR = 4.08; 95% CI, 2.18 - 7.63; P < 0.001). Non-linear associations were observed between BMI and fractures: A J-curve for total, lumbar, and femoral neck fractures, and no statistical change for other types of fractures. Underweight was found to be a risk factor for other types of fracturess after adjusting for BMD (OR = 2.29; 95% CI, 1.09 - 4.80; P < 0.001). Osteoporosis and osteopenia were identified as risk factors for almost all sites of fracture when compared to normal bone mass. CONCLUSIONS: Underweight has a protective effect on total and lumbar spine fractures in Chinese women, while obesity poses a risk factor for total, lumbar, and femoral neck fractures. The effect of BMI on fractures may be mainly mediated by BMD.

Electrogenerated Chemiluminescence Imaging of Single-Atom Nanocatalysts.

Single-atom catalysts (SACs), distinguished by their maximum atom efficiency and precise control over the coordination and electronic properties of individual atoms, show great promise in electrocatalysis. Gaining a comprehensive understanding of the electrochemical performance of SACs requires the screening of electron transfer process at micro/nano scale. This research pioneers the use of electrogenerated chemiluminescence microscopy (ECLM) to observe the electrocatalytic reactions at individual SACs. It boasts sensitivity at the single photon level and temporal resolution down to 100 ms, enabling real-time capture of the electrochemical behavior of individual SACs during potential sweeping. Leveraging the direct correlation between ECL emission and heterogeneous electron transfer processes, we introduced photon flux density for quantitative analysis, unveiling the electrocatalytic efficiency of individual SACs. This approach systematically reveals the relationship between SACs based on different metal atoms and their peroxidase (POD)-like activity. The outcomes contribute to a fundamental understanding of SACs and pave the way for designing SACs with diverse technological and industrial applications.