Contemporary Evaluation of Work-Life Integration and Wellbeing in US Surgical Residents: A National Mixed-Methods Study.

BACKGROUND: The demands of surgical training present challenges for work-life integration (WLI). We sought to identify factors associated with work-life conflicts and to understand how programs support WLI. STUDY DESIGN: A cross-sectional national survey conducted after the 2020 American Board of Surgery In-Training Examination queried 4 WLI items. Multivariable regression models evaluated factors associated with (1) work-life conflicts and (2) well-being (career dissatisfaction, burnout, thoughts of attrition, suicidality). Semi-structured interviews conducted with faculty and residents from 15 general surgery programs were analyzed to identify strategies for supporting WLI. RESULTS: Of 7,233 residents (85.5% response rate) 5,133 had data available on work-life conflicts. 44.3% reported completing non-educational task-work at home, 37.6% were dissatisfied with time for personal life (e.g., hobbies), 51.6% with maintaining healthy habits (e.g., exercise), and 48.0% with performing routine health maintenance (e.g., dentist). In multivariable analysis, parents and female residents were more likely to report work-life conflicts (all p<0.05). After adjusting for other risk factors (e.g., duty-hour violations, and mistreatment), residents with work-life conflicts remained at increased risk for career dissatisfaction, burnout, thoughts of attrition, and suicidality (all p<0.05). Qualitative analysis revealed interventions for supporting WLI including (1) protecting time for health maintenance (e.g., therapy); (2) explicitly supporting life outside of work (e.g., prioritizing time with family); and (3) allowing meaningful autonomy in scheduling (e.g., planning for major life events). CONCLUSIONS: Work-life conflicts are common among surgical residents and are associated with poor resident well-being. Well-designed program-level interventions have the potential to support WLI in surgical residency.

Subsurface A-site vacancy activates lattice oxygen in perovskite ferrites for methane anaerobic oxidation to syngas.

Tuning the oxygen activity in perovskite oxides (ABO3) is promising to surmount the trade-off between activity and selectivity in redox reactions. However, this remains challenging due to the limited understanding in its activation mechanism. Herein, we propose the discovery that generating subsurface A-site cation (Lasub.) vacancy beneath surface Fe-O layer greatly improved the oxygen activity in LaFeO3, rendering enhanced methane conversion that is 2.9-fold higher than stoichiometric LaFeO3 while maintaining high syngas selectivity of 98% in anaerobic oxidation. Experimental and theoretical studies reveal that absence of Lasub.-O interaction lowered the electron density over oxygen and improved the oxygen mobility, which reduced the barrier for C-H bond cleavage and promoted the oxidation of C-atom, substantially boosting methane-to-syngas conversion. This discovery highlights the importance of A-site cations in modulating electronic state of oxygen, which is fundamentally different from the traditional scheme that mainly credits the redox activity to B-site cations and can pave a new avenue for designing prospective redox catalysts.

BMSC­derived exosome­mediated miR­25­3p delivery protects against myocardial ischemia/reperfusion injury by constraining M1­like macrophage polarization.

Myocardial ischemia/reperfusion injury (MIRI) is a significant challenge in the management of myocardial ischemic disease. Extensive evidence suggests that the macrophage­mediated inflammatory response may play a vital role in MIRI. Mesenchymal stem cells and, in particular, exosomes derived from these cells, may be key mediators of myocardial injury and repair. However, whether exosomes protect the heart by regulating the polarization of macrophages and the exact mechanisms involved are poorly understood. The present study aimed to determine whether exosomes secreted by bone marrow mesenchymal stem cells (BMSC­Exo) harboring miR­25­3p can alter the phenotype of macrophages by affecting the JAK2/STAT3 signaling pathway, which reduces the inflammatory response and protects against MIRI. An in vivo MIRI model was established in rats by ligating the anterior descending region of the left coronary artery for 30 min followed by reperfusion for 120 min, and BMSC­Exo carrying miR­25­3p (BMSC­Exo­25­3p) were administered through tail vein injection. A hypoxia­reoxygenation model of H9C2 cells was established, and the cells were cocultured with BMSC­Exo­25­3p in vitro. The results of the present study demonstrated that BMSC­Exo or BMSC­Exo­25­3p could be taken up by cardiomyocytes in vivo and H9C2 cells in vitro. BMSC­Exo­25­3p demonstrated powerful cardioprotective effects by decreasing the cardiac infarct size, reducing the incidence of malignant arrhythmias and attenuating myocardial enzyme activity, as indicated by lactate dehydrogenase and creatine kinase levels. It induced M1­like macrophage polarization after myocardial ischemia/reperfusion (I/R), as evidenced by the increase in iNOS expression through immunofluorescence staining and upregulation of proinflammatory cytokines through RT­qPCR, such as interleukin­1ß (IL­1ß) and interleukin­6 (IL­6). As hypothesized, BMSC­Exo­25­3p inhibited M1­like macrophage polarization and proinflammatory cytokine expression while promoting M2­like macrophage polarization. Mechanistically, the JAK2/STAT3 signaling pathway was activated after I/R in vivo and in LPS­stimulated macrophages in vitro, and BMSC­Exo­25­3p pretreatment inhibited this activation. The results of the present study indicate that the attenuation of MIRI by BMSC­Exo­25­3p may be related to JAK2/STAT3 signaling pathway inactivation and subsequent inhibition of M1­like macrophage polarization.

Feasibility study of use of desflurane combined with dexmedetomidine in inhibiting postoperative neurocognitive disorders in elderly patients under general anesthesia: A perspective study.

This study aimed to explore whether the combined application of desflurane and dexmedetomidine (Dex) reduces the occurrence of postoperative neurocognitive disorders (PND) in patients. We selected patients in our hospital who underwent surgery under general anesthesia, and divided them into two groups: Dex and desflurane (Dex + Des) and desflurane (Des) groups. The data of patients were collected and the Mini-Mental State Examination (MMSE) score was used to assess cognitive status. The blood cell counts were determined preoperatively and on postoperative days 1, 3, and 6, and the percentage of neutrophils and lymphocytes were also recorded. The statistical methods used were the independent-samples t-test and the χ 2 test. Pearson's correlation was used to analyze the correlation between PND and inflammation. The incidence of PND in the Dex + Des group was lower than that in the Des group. The postoperative MMSE scores in the Dex + Des group were higher than those in the Des group (p = 0.032). The percentage of neutrophils in the Dex + Des group was significantly lower than that in the Des group on the first and third days after surgery (p = 0.007; p = 0.028). The MMSE scores on the first day after surgery were negatively correlated with the multiple changes in white blood counts and the percentage of neutrophils (r = -0.3038 and -0.3330). Dex combined with Des reduced the incidence of PND and reduced the postoperative inflammatory cell counts.

Multi-Omics Insights into Disulfidptosis-Related Genes Reveal RPN1 as a Therapeutic Target for Liver Cancer.

Disulfidptosis, a newly identified mode of programmed cell death, is yet to be comprehensively elucidated with respect to its multi-omics characteristics in tumors, specific pathogenic mechanisms, and antitumor functions in liver cancer. This study included 10,327 tumor and normal tissue samples from 33 cancer types. In-depth analyses using various bioinformatics tools revealed widespread dysregulation of disulfidptosis-related genes (DRGs) in pan-cancer and significant associations with prognosis, genetic variations, tumor stemness, methylation levels, and drug sensitivity. Univariate and multivariate Cox regression and LASSO regression were used to screen and construct prognosis-related hub DRGs and predictive models in the context of liver cancer. Subsequently, single cell analysis was conducted to investigate the subcellular localization of RPN1, a hub DRG, in various solid tumors. Western blotting was performed to validate the expression of RPN1 at both cellular and tissue levels. Additionally, functional experiments, including CCK8, EdU, clone, and transwell assays, indicated that RPN1 knockdown promoted the proliferative and invasive capacities of liver cancer cells. Therefore, this study elucidated the multi-omics characteristics of DRGs in pan-cancer and established a prognostic model for liver cancer. Additionally, this study revealed the molecular functions of RPN1 in liver cancer, suggesting its potential as a therapeutic target for this disease.

Systematic Structural Modification of Squaraine Dye for Near-Infrared Window One and Two Multiplexed In Vivo Imaging and Photothermal Therapy.

Due to the wide application of reporter gene-related visible/NIR-I bioluminescent imaging, multiplexed fluorescence imaging across visible/NIR-I/NIR-II has excellent potential in biomedical research. However, in vivo multiplexed imaging applications across those regions have rarely been reported due to the lack of proper fluorophores. Herein, nine squaraine dyes, which exhibit diverse adsorption and emission wavelengths, were synthesized. Among them, water-soluble SQ 710-5k and SQ 905 were found to have significant absorption differences, which allowed the tumor and lymph nodes to be identified. Then, for the first time, six-channel multiplexed fluorescence imaging across visible/NIR-I/II was achieved by coordination with reporter gene-related bioluminescent phosphors. Additional research revealed that SQ 710-5k exhibited higher-quality blood vessels and tumor imaging in NIR-II. H-aggregates SQ 905 demonstrated a high photothermal conversion efficiency for photothermal therapy. This study proposed an approach to creating small molecular dyes that coordinate with reporter gene-related bioluminescent phosphors for six-color fluorescence imaging.

(+)/(-)-Gerbeloid A, a pair of unprecedented coumarin-based polycyclic meroterpenoid enantiomers from Gerbera piloselloides: Structural elucidation, semi-synthesis, and lipid-lowering activity.

A pair of coumarin-based polycyclic meroterpenoid enantiomers (+)/(-)-gerbeloid A [(+)-1a and (-)-1b] were isolated from the medicinal plant Gerbera piloselloides, which have a unique caged oxatricyclo [4.2.2.03,8] decene scaffold. Their planar and three-dimensional structures were exhaustively characterized by comprehensive spectroscopic data and X-ray diffraction analysis. Guided by the hypothetical biosynthetic pathway, the biomimetic synthesis of racemic 1 was achieved using 4-hydroxy-5-methylcoumarin and citral as the starting material via oxa-6π electrocyclization and intramolecular [2 + 2] photocycloaddition. Subsequently, the results of the biological activity assay demonstrated that both (+)-1a and (-)-1b exhibited potent lipid-lowering effects in 3T3-L1 adipocytes and the high-fat diet zebrafish model. Notably, the lipid-lowering activity of (+)-1a is better than that of (-)-1b at the same concentration, and molecular mechanism study has shown that (+)-1a and (-)-1b impairs adipocyte differentiation and stimulate lipolysis by regulating C/EBPα/PPARγ signaling and Perilipin signaling in vitro and in vivo. Our findings provide a promising drug model molecule for the treatment of obesity.

PD-1/PD-L1 Provides Protective Role in Hypoxia-Induced Pulmonary Vascular Remodeling.

BACKGROUND: Hypoxia-induced pulmonary hypertension (HPH) is a T helper 17 cell response-driven disease, and PD-1 (programmed cell death 1)/PD-L1 (programmed cell death-ligand 1) inhibitor-associated pulmonary hypertension has been reported recently. This study is designed to explore whether the PD-1/PD-L1 pathway participates in HPH via regulating endothelial dysfunction and T helper 17 cell response. METHODS: Lung tissue samples were obtained from eligible patients. Western blotting, immunohistochemistry, and immunofluorescence techniques were used to assess protein expression, while immunoprecipitation was utilized to detect ubiquitination. HPH models were established in C57BL/6 WT (wild-type) and PD-1-/- mice, followed by treatment with PD-L1 recombinant protein. Adeno-associated virus vector delivery was used to upregulate PD-L1 in the endothelial cells. Endothelial cell function was assessed through assays for cell angiogenesis and adhesion. RESULTS: Expression of the PD-1/PD-L1 pathway was downregulated in patients with HPH and mouse models, with a notable decrease in PD-L1 expression in endothelial cells compared with the normoxia group. In comparison to WT mice, PD-1-/- mice exhibited a more severe HPH phenotype following exposure to hypoxia, However, administration of PD-L1 recombinant protein and overexpression of PD-L1 in lung endothelial cells mitigated HPH. In vitro, blockade of PD-L1 with a neutralizing antibody promoted endothelial cell angiogenesis, adhesion, and pyroptosis. Mechanistically, hypoxia downregulated PD-L1 protein expression through ubiquitination. Additionally, both in vivo and in vitro, PD-L1 inhibited T helper 17 cell response through the PI3K (phosphoinositide 3-kinase)/AKT (protein kinase B)/mTOR (mammalian target of rapamycin) pathway in HPH. CONCLUSIONS: PD-1/PD-L1 plays a role in ameliorating HPH development by inhibiting T helper 17 cell response through the PI3K/AKT/mTOR pathway and improving endothelial dysfunction, suggesting a novel therapeutic indication for PD-1/PD-L1-based immunomodulatory therapies in the treatment of HPH.

Single-port versus traditional three-port laparoscopic total extraperitoneal inguinal hernia repair: A single-centre, prospective, randomised study.

OBJECTIVE: To explore the efficacy and safety of single-incision laparoscopic (SIL) technique compared with the traditional three-port total extraperitoneal (TEP) technique for inguinal hernia repair. METHODS: This prospective, randomised study involved patients who underwent surgery for inguinal hernia at our hospital from December 2021 to July 2023. Patients were randomly assigned to SIL-TEP or TEP groups based on a computer-generated random number table. Perioperative clinical indicators for the surgical approaches were evaluated. RESULTS: Of the 127 patients eligible for study, 66 were randomised to the SIL-TEP group and 61 to the TEP group. The operation time for SIL-TEP was significantly longer than for TEP but the time to return to normal activities was significantly shorter and short-term pain score was significantly lower. There were no differences between groups in intraoperative blood loss, postoperative hospital stays, pain relief time, hospitalization costs or cosmetic satisfaction scores. CONCLUSION: While SIL-TEP is more challenging than TEP for hernia repair, we found that at our centre it is comparable with regard to overall safety and feasibility. Further studies are needed to validate our findings.

Investigating the Mechanism of Microwave-Assisted Enzymolysis Synergized with Magnetic Bead Adsorption for Reducing Ovalbumin Allergenicity through Biomass Spectrometry Analysis.

This study found that, after microwave treatment at 560 W for 30 s, alkaline protease enzymolysis significantly reduced the allergenicity of ovalbumin (OVA). Furthermore, specific adsorption of allergenic anti-enzyme hydrolyzed peptides in the enzymatic products by immunoglobulin G (IgG) bound to magnetic bead further decreased the allergenicity of OVA. The results indicated that microwave treatment disrupts the structure of OVA, increasing the accessibility of OVA to the alkaline protease. A comparison between 17 IgG-binding epitopes identified through high-performance liquid chromatography-higher energy collisional dissociation-tandem mass spectrometry and previously reported immunoglobulin E (IgE)-binding epitopes revealed a complete overlap in binding epitopes at amino acids (AA)125-135, AA151-158, AA357-366, and AA373-381. Additionally, partial overlap was observed at positions AA41-59, AA243-252, and AA320-340. Consequently, these binding epitopes were likely pivotal in eliciting the allergic reaction to OVA, warranting specific attention in future studies. In conclusion, microwave-assisted enzymolysis synergized with magnetic bead adsorption provides an effective method to reduce the allergenicity of OVA.

Different dosage forms of GnRHa with endocrine therapy in premenopausal hormone Receptor-Positive breast cancer.

BACKGROUND: Despite the wide use of a three-month gonadotropin-releasing hormone agonist (3M GnRHa) for ovarian function suppression (OFS) in premenopausal breast cancer patients, it remains unclear whether it is as effective and safe as a one-month GnRHa regimen (1M GnRHa) when combined with selective estrogen receptor modulators (SERMs) or aromatase inhibitors (AIs), especially in younger patients. METHODS: This retrospective cohort study included 1109 premenopausal hormone receptor-positive (HR+) breast cancer patients treated with GnRHa plus SERM or AI. The estradiol (E2) inhibition rate within 1-24 months after treatment with 1M or 3M GnRHa in cohorts and different subgroups was analyzed. RESULTS: Following 1:1 propensity score matching, 950 patients with a mean age of 39 years and a median follow-up of 46 months were included. Both the 1M and 3M groups achieved >90% E2 inhibition within 24 months (94.53% vs 92.84%, 95% CI (-4.78%, 1.41%)), confirming the non-inferiority of 3M GnRHa. Both 1M and 3M GnRHa rapidly and consistently reduced E2 levels. 60 (6.3%) patients experienced incomplete ovarian function suppression (iOFS), with similar rates in the 1M and 3M groups (5.5% vs 7.2%). iOFS mainly occurred within the first 12 months, with age <40 years and no prior chemotherapy being the risk factors. Similar disease-free survival (DFS) and overall survival (OS) were found in the 1M and 3M groups, and in patients with complete and incomplete OFS (p > .05). CONCLUSIONS: The OFS with 3M GnRHa was not inferior to that with 1M GnRHa, regardless of age or combination with a SERM or an AI.

Effects of cofermentation of Saccharomyces cerevisiae and different lactic acid bacteria on the organic acid content, soluble sugar content, biogenic amines, phenol content, antioxidant activity and aroma of prune wine.

To determine the effect of cofermentation of Saccharomyces cerevisiae and different LABs on prune wine quality, this study compared phenolic compounds, organic acids, soluble sugars, biogenic amines and volatile flavor compounds among different treatments. The results showed that inoculation of LAB increased DPPH and total flavonoid content. Malic acid content was reduced in HS, HB and HF. Histamine content in S, F and B was lower than the limits in French and Australian wines. 15 phenolic compounds were identified. Yangmeilin and chlorogenic acid were detected only in HS, HF and HB. 51 volatile flavor compounds were identified, esters being the most diverse and abundant. 14 volatile flavor compounds with OAV > 1 contributed highly to the aroma of prune wine. 9 chemical markers including resveratrol, rutin, and catechin were screened to explain intergroup differences by OPLS-DA. This study provides new insights into the processing and quality analysis of prunes.

Lung sparing in MR-guided non-adaptive SBRT treatment of peripheral lung tumors.

Objective.We aim to: (1) quantify the benefits of lung sparing using non-adaptive magnetic resonance guided stereotactic body radiotherapy (MRgSBRT) with advanced motion management for peripheral lung cancers compared to conventional x-ray guided SBRT (ConvSBRT); (2) establish a practical decision-making guidance metric to assist a clinician in selecting the appropriate treatment modality.Approach.Eleven patients with peripheral lung cancer who underwent breath-hold, gated MRgSBRT on an MR-guided linear accelerator (MR linac) were studied. Four-dimensional computed tomography (4DCT)-based retrospective planning using an internal target volume (ITV) was performed to simulate ConvSBRT, which were evaluated against the original MRgSBRT plans. Metrics analyzed included planning target volume (PTV) coverage, various lung metrics and the generalized equivalent unform dose (gEUD). A dosimetric predictor for achievable lung metrics was derived to assist future patient triage across modalities.Main results.PTV coverage was high (median V100% > 98%) and comparable for both modalities. MRgSBRT had significantly lower lung doses as measured by V20 (median 3.2% versus 4.2%), mean lung dose (median 3.3 Gy versus 3.8 Gy) and gEUD. Breath-hold, gated MRgSBRT resulted in an average reduction of 47% in PTV volume and an average increase of 19% in lung volume. Strong correlation existed between lung metrics and the ratio of PTV to lung volumes (RPTV/Lungs) for both modalities, indicating that RPTV/Lungsmay serve as a good predictor for achievable lung metrics without the need for pre-planning. A threshold value of RPTV/Lungs< 0.035 is suggested to achieve V20 < 10% using ConvSBRT. MRgSBRT should otherwise be considered if the threshold cannot be met.Significance.The benefits of lung sparing using MRgSBRT were quantified for peripheral lung tumors; RPTV/Lungswas found to be an effective predictor for achievable lung metrics across modalities. RPTV/Lungscan assist a clinician in selecting the appropriate modality without the need for labor-intensive pre-planning, which has significant practical benefit for a busy clinic.

Global distribution of zoonotic digenetic trematodes: a scoping review.

BACKGROUND: Digenetic trematodes, including blood flukes, intestinal flukes, liver flukes, lung flukes, and pancreatic flukes, are highly diverse and distributed widely. They affect at least 200 million people worldwide, so better understanding of their global distribution and prevalence are crucial for controlling and preventing human trematodiosis. Hence, this scoping review aims to conduct a comprehensive investigation on the spatio-temporal distribution and epidemiology of some important zoonotic digenetic trematodes. METHODS: We conducted a scoping review by searching PubMed, Web of Science, Google Scholar, China National Knowledge Infrastructure, and Wanfang databases for articles, reviews, and case reports of zoonotic digenetic trematodes, without any restrictions on the year of publication. We followed the inclusion and exclusion criteria to identify relevant studies. And relevant information of the identified studies were collected and summarized. RESULTS: We identified a total of 470 articles that met the inclusion criteria and were included in the review finally. Our analysis revealed the prevalence and global distribution of species in Schistosoma, Echinostoma, Isthmiophora, Echinochasmus, Paragonimus, Opisthorchiidae, Fasciolidae, Heterophyidae, and Eurytrema. Although some flukes are distributed worldwide, developing countries in Asia and Africa are still the most prevalent areas. Furthermore, there were some overlaps between the distribution of zoonotic digenetic trematodes from the same genus, and the prevalence of some zoonotic digenetic trematodes was not entirely consistent with their global distribution. The temporal disparities in zoonotic digenetic trematodes may attribute to the environmental changes. The gaps in our knowledge of the epidemiology and control of zoonotic digenetic trematodes indicate the need for large cohort studies in most countries. CONCLUSIONS: This review provides important insights into the prevalence and global distribution of some zoonotic digenetic trematodes, firstly reveals spatio-temporal disparities in these digenetic trematodes. Countries with higher prevalence rate could be potential sources of transmitting diseases to other areas and are threat for possible outbreaks in the future. Therefore, continued global efforts to control and prevent human trematodiosis, and more international collaborations are necessary in the future.

Copper-Catalyzed Borrowing Hydrogen Reaction for α-Alkylation of Amides with Alcohols.

We report the first example of copper-catalyzed α-alkylation of acetamides with alcohols via a borrowing hydrogen strategy. Catalyzed by the in situ-generated copper particles, acetamides and various substituted benzyl or alkyl alcohols were transformed into functionalized amides in good yields with excellent selectivity. Compared with previous work, this process is simple using commercially available Cu(OAc)2 as a precatalyst, without an additional ligand or a metal complex, and easier. Mechanistic studies revealed that aldehyde and α,ß-unsaturated amides were the intermediates of this reaction and also disclosed the role of copper in alcohol dehydrogenation and C═C bond hydrogenation.

Daphne genkwa: Ethnopharmacology, phytochemistry and pharmacology of an important traditional Chinese medicine.

Daphne genkwa, as a traditional medicine, is widely distributed in China, Korea and Vietnam. In China, the dried flower buds of this plant are named "Yuanhua". It has the ability to effectively promote urination, eliminate phlegm and alleviate cough, eliminate parasites and cure of scabies, with a broad spectrum of pharmacological effects and considerable clinical efficacy. This paper provides a summary and classification of the main chemical constituents of D. genkwa based on a review of relevant domestic and foreign literature. It also outlines the current research status of traditional clinical usage, pharmacological effects, and toxicity of D. genkwa. The aim is to provide a theoretical basis for further study of D. genkwa and its potential new clinical applications.

Multifunctional composite soluble microneedle patch based on "one stone, three birds" strategy for promoting the healing of infectious wounds.

The colonisation of microorganisms such as bacteria forms a biofilm barrier on the wound's surface, preventing or delaying the penetration of antibacterial drugs. At the same time, continuous bacterial infection can cause oxidative stress and an inflammatory response and hinder angiogenesis, resulting in difficult wound healing. Based on the "one stone, three birds" strategy, a multi-functional nanoparticle composite soluble microneedle was designed and developed to solve this dilemma better. Ginsenoside-liposomes(R-Lipo) were prepared by ginsenoside Rg3, which had the effect of promoting repair, instead of cholesterol, and loaded with berberine (Ber), the antibacterial component of Coptis, together with polydopamine (PDA), which had anti-inflammatory and antioxidant properties, into microneedles based on hyaluronic acid (PDA/R-Lipo@BerMN). PDA/R-Lipo@BerMN tip can penetrate and destroy the integrity of the biofilm, dissolve under the action of hyaluronidase in the skin, and gradually release the drug to achieve rapid antibacterial, anti-inflammatory, antioxidant, and proliferation. As expected, the PDA/R-Lipo@BerMN patch effectively cleared ROS during wound closure, further promoted M2 macrophage polarisation, eradicated bacterial infection, and regulated the immune microenvironment, promoting inflammation suppression, collagen deposition, angiogenesis, and tissue regeneration.

Evolution of catalyst design for controlled synthesis of chiral single-walled carbon nanotubes.

Single-walled carbon nanotubes (SWCNTs) possess superb properties originating from their unique chiral structures. However, accurately controlling the structure of SWCNTs remains challenging due to the structural similarities of their chiral structures, which hinders their widespread application in various fields, particularly in electronics. In recent years, much effort has been devoted to preparing single chiral SWCNTs by adopting three constructive strategies, including growth condition control for structurally unstable liquid catalysts, employing stable solid catalyst design, and pre-synthesis of carbon seeds with a well-defined shape. This review comprehensively discusses the state-of-the-art developments in these approaches as well as their advantages and disadvantages. Moreover, insights into the key challenges and future directions are provided for acquiring chirally pure SWCNTs.

Spontaneous chromosome instability and tissue culture-induced karyotypic alteration in wheat-Thinopyrum intermedium alien addition lines.

MAIN CONCLUSION: Wheat lines harboring wild-relative chromosomes can be karyotypically unstable during long-term maintenance. Tissue culture exacerbates chromosomal instability but appears inefficient to induce somatic homoeologous exchange between alien and wheat chromosomes. We assessed if long-term refrigerator storage with regular renewal via self-fertilization, a widely used practice for crop germplasm maintenance, would ensure genetic fidelity of alien addition lines, and explored the possibility of inducing somatic homoeologues exchange by tissue culture. We cytogenetically characterized sampled stock seeds of originally confirmed 12 distinct wheat-Thinopyrum intermedium alien addition lines (dubbed TAI lines), and subjected immature embryos of the TAI lines to tissue culture. We find eight of the 12 TAI lines were karyotypically departed from their original identity as bona fide disomic alien addition lines due to extensive loss of whole-chromosomes of both Th. intermedium and wheat origins during the ca. 3-decade storage. Rampant numerical chromosome variations (NCVs) involving both alien and wheat chromosomes were detected in regenerated plants of all 12 studied TAI lines, but at variable rates among the wheat sub-genomes and chromosomes. Compared with NCVs, structural chromosome variations (SCVs) occurred at substantially lower rates, and no SCV involving the added alien chromosomes was observed. The NCVs manifested only moderate effects on phenotypes of the regenerated plants under field conditions.