Overcrowded 14,14'-Bidibenzo[a,j]anthracenes: Challenges in Syntheses and Atypical Property of Lacking Symmetry-Breaking Charge Transfer (SBCT).

14,14'-Bidibenzo[a,j]anthracenes (BDBAs) were prepared by iridium-catalyzed annulation of 5,5'-biterphenylene with alkynes. The molecular geometries of overcrowded BDBAs were verified by X-ray crystallography. The two dibenzo[a,j]anthryl moieties are connected through the sterically hindered 14 positions, resulting in highly distorted molecular halves. The conformation with a small twist angle between two molecular halves can minimize steric conflicts between the substituents at 1 and 13 positions and the carbon atoms of the central axis, as well as steric clashes between those substituents. One such example is octafluoro-substituted BDBA, where the interplanar angle between two anthryl moieties is approximately 31° (currently the lowest reported value, cf. 81° in 9,9'-bianthracene). The intramolecular interactions and electronic couplings between two molecular halves resulted in upfield 1H NMR signals, redshifted absorption and emission bands, and a reduced HOMO-LUMO gap. Photodynamic investigations on BDBAs indicated that the formation of the conventional symmetry-breaking charge transfer (SBCT) state was suspended by restricted rocking around the central C-C bond. Such a mechanism associated with this highly constrained conformation was examined for the first time.

A New Series of Sandwich-Type 5,5'-Biterphenylenes: Synthetic Challenge, Structural Uniqueness and Photodynamics.

A new series of biaryls, bi-linear-terphenylenes (BLTPs), were prepared using the tert-butyllithium-mediated cyclization as the key synthetic step. The three-dimensional structures of the studied compounds were verified using X-ray crystallography and DFT calculations. Tetraaryl(ethynyl)-substituted BLTPs are highly crowded molecules, and the internal rotation around the central C-C bond is restricted due to a high barrier (>50 kcal/mol). These structures contain several aryl/terphenylenyl/aryl sandwiches, where the through-space π-π (TSPP) interactions are strongly reflected in the shielding of 1 H NMR chemical shifts, reduction of oxidation potentials, increasing aromaticity of the central six-membered ring and decreasing antiaromaticity of the four-membered rings in a terphenylenyl moiety based on NICS(0) and iso-chemical shielding surfaces. Despite the restricted C-C bond associated intramolecular TSPP interactions for BLTPs in the ground state, to our surprise, the electronic coupling between two linear terphenylenes (LTPs) in BLTPs in the excited state is weak, so that the excited-state behavior is dominated by the corresponding monomeric LTPs. In other words, all BLTPs undergo ultrafast relaxation dynamics via strong exciton-vibration coupling, acting as a blue-light absorber with essentially no emission.

Effect of Osteoporosis Treatments on Osteoarthritis Progression in Postmenopausal Women: A Review of the Literature.

PURPOSE OF REVIEW: The purpose of this literature review was to determine if medications used to treat osteoporosis are also effective for treating osteoarthritis (OA). RECENT FINDINGS: A total of 40 relevant articles were identified. Studies were categorized into those (1) discussing estrogen and selective estrogen receptor modulators (SERMs), (2) bisphosphonates, (3) parathyroid hormone (PTH) analogs, and (4) denosumab, and (5) prior review articles. A large amount of evidence suggests that estrogen and SERMs are effective at reducing OA symptoms and disease progression. Evidence suggests that bisphosphonates, the most common medications used to treat osteoporosis, can reduce OA symptoms and disease progression. In vivo studies suggest that PTH analogs may improve the cartilage destruction associated with OA; however, few human trials have examined its use for OA. Denosumab is approved to treat osteoporosis, bone metastases, and certain types of breast cancer, but little study has been done with respect to its effect on OA. The current evidence indicates that medications used to treat osteoporosis are also effective for treating OA. Estrogen, SERMs, and bisphosphonates have the most potential as OA therapies. Less is known regarding the effectiveness of PTH analogs and denosumab in OA, and more research is needed.

Exosome lncRNA IFNG-AS1 derived from mesenchymal stem cells of human adipose ameliorates neurogenesis and ASD-like behavior in BTBR mice.

BACKGROUND: The transplantation of exosomes derived from human adipose-derived mesenchymal stem cells (hADSCs) has emerged as a prospective cellular-free therapeutic intervention for the treatment of neurodevelopmental disorders (NDDs), as well as autism spectrum disorder (ASD). Nevertheless, the efficacy of hADSC exosome transplantation for ASD treatment remains to be verified, and the underlying mechanism of action remains unclear. RESULTS: The exosomal long non-coding RNAs (lncRNAs) from hADSC and human umbilical cord mesenchymal stem cells (hUCMSC) were sequenced and 13,915 and 729 lncRNAs were obtained, respectively. The lncRNAs present in hADSC-Exos encompass those found in hUCMSC-Exos and are associated with neurogenesis. The biodistribution of hADSC-Exos in mouse brain ventricles and organoids was tracked, and the cellular uptake of hADSC-Exos was evaluated both in vivo and in vitro. hADSC-Exos promote neurogenesis in brain organoid and ameliorate social deficits in ASD mouse model BTBR T + tf/J (BTBR). Fluorescence in situ hybridization (FISH) confirmed lncRNA Ifngas1 significantly increased in the prefrontal cortex (PFC) of adult mice after hADSC-Exos intraventricular injection. The lncRNA Ifngas1 can act as a molecular sponge for miR-21a-3p to play a regulatory role and promote neurogenesis through the miR-21a-3p/PI3K/AKT axis. CONCLUSION: We demonstrated hADSC-Exos have the ability to confer neuroprotection through functional restoration, attenuation of neuroinflammation, inhibition of neuronal apoptosis, and promotion of neurogenesis both in vitro and in vivo. The hADSC-Exos-derived lncRNA IFNG-AS1 acts as a molecular sponge and facilitates neurogenesis via the miR-21a-3p/PI3K/AKT signaling pathway, thereby exerting a regulatory effect. Our findings suggest a potential therapeutic avenue for individuals with ASD.

Maximizing Polysaccharides and Phycoerythrin in Porphyridium purpureum via the Addition of Exogenous Compounds: A Response-Surface-Methodology Approach.

Phycoerythrin and polysaccharides have significant commercial value in medicine, cosmetics, and food industries due to their excellent bioactive functions. To maximize the production of biomass, phycoerythrin, and polysaccharides in Porphyridium purpureum, culture media were supplemented with calcium gluconate (CG), magnesium gluconate (MG) and polypeptides (BT), and their optimal amounts were determined using the response surface methodology (RSM) based on three single-factor experiments. The optimal concentrations of CG, MG, and BT were determined to be 4, 12, and 2 g L-1, respectively. The RSM-based models indicated that biomass and phycoerythrin production were significantly affected only by MG and BT, respectively. However, polysaccharide production was significantly affected by the interactions between CG and BT and those between MG and BT, with no significant effect from BT alone. Using the optimized culture conditions, the maximum biomass (5.97 g L-1), phycoerythrin (102.95 mg L-1), and polysaccharide (1.42 g L-1) concentrations met and even surpassed the model-predicted maximums. After optimization, biomass, phycoerythrin, and polysaccharides concentrations increased by 132.3%, 27.97%, and 136.67%, respectively, compared to the control. Overall, this study establishes a strong foundation for the highly efficient production of phycoerythrin and polysaccharides using P. purpureum.

Therapeutic advantage of teriparatide in very elderly patients with proximal femoral fractures: a functional and BMD analysis.

BACKGROUND: Teriparatide, a recombinant parathyroid hormone, is pivotal in osteoporosis treatment, particularly in post-surgical recovery for hip fractures. This study investigates its efficacy in functional recovery post-hip fracture surgery in elderly patients, a demographic particularly susceptible to osteoporotic fractures. METHODS: In this retrospective cohort study, 150 elderly patients with proximal femoral fractures undergoing open reduction and internal fixation were enrolled. They were categorized into two groups: receiving 20 µg of daily teriparatide injections for 18 months and receiving standard antiresorptive medications during a 24-month follow-up. Detailed records of patient demographics, Fracture Risk Assessment Tool scores, and comorbidities were kept. Key outcomes, including bone mineral density (BMD) and functional scores (Barthel Index and Visual Analog Scale for hip pain), were evaluated at 3 and 24 months post-surgery. RESULTS: Out of the original cohort, 126 patients (20 men and 106 women with an average age of 85.5 ± 9.3 years) completed the study. The teriparatide group exhibited significant enhancements in both functional scores and BMD when compared to the control group. Notably, functional improvements were less pronounced in male patients compared to female patients. Additionally, the incidence of new fractures was markedly lower in the teriparatide group. CONCLUSION: Administering teriparatide daily for 18 months post-surgery for proximal femoral fractures significantly benefits very elderly patients by improving functionality and bone density, with observed differences in recovery between genders. These results reinforce the efficacy of teriparatide as a potent option for treating osteoporosis-related fractures in the elderly and highlight the importance of considering gender-specific treatment and rehabilitation strategies.

Femoral neck system versus multiple cannulated screws for the fixation of Pauwels classification type II femoral neck fractures in older female patients with low bone mass.

BACKGROUND: Femoral neck fractures in older adult patients are a major concern and often necessitate surgical intervention. This study compared the clinical outcomes of 2 surgical techniques: the femoral neck system (FNS) and cannulated compression screws (CCSs). METHODS: A total of 40 female patients (mean age 73.50 ± 11.55 years) with femoral neck fractures of Pauwels classification type II and receiving surgical fixation between 2020 and 2022 were enrolled. The patients were categorized into an FNS group (n = 12) or a CCS group (n = 28), and surgical duration, intraoperative blood loss, length of hospital stay, and incidence of postoperative adverse events were analyzed. RESULTS: No significant intergroup differences in demographic characteristics were discovered. The mean surgical duration for all patients was 52.88 ± 22.19 min, with no significant difference between the groups. However, the FNS group experienced significantly higher intraoperative blood loss (P = 0.002) and longer hospital stay (P = 0.023) than did the CCS group. The incidence of osteonecrosis was higher in the CCS group, whereas the incidence of nonunion or malunion was higher in the FNS group. The surgical method did not appear to be a significant risk factor. The main risk factor for revision surgery was longer duration until the first adverse event (P = 0.015). CONCLUSION: The FNS does not appear to provide superior surgical outcomes compared with CCSs in older adult women with Pauwels classification type II femoral neck fractures. A longer duration between surgical fixation and the first adverse event before stabilization of the fracture site may be a risk factor for revision surgery.

Cooperation of Different Active Sites to Promote CO2 Electroreduction to Multi-carbon Products at Ampere-Level.

Electroreduction of CO2 to C2+ products provides a promising strategy for reaching the goal of carbon neutrality. However, achieving high selectivity of C2+ products at high current density remains a challenge. In this work, we designed and prepared a multi-sites catalyst, in which Pd was atomically dispersed in Cu (Pd-Cu). It was found that the Pd-Cu catalyst had excellent performance for producing C2+ products from CO2 electroreduction. The Faradaic efficiency (FE) of C2+ products could be maintained at approximately 80.8 %, even at a high current density of 0.8 A cm-2 for at least 20 hours. In addition, the FE of C2+ products was above 70 % at 1.4 A cm-2. Experiments and density functional theory (DFT) calculations revealed that the catalyst had three distinct catalytic sites. These three active sites allowed for efficient conversion of CO2, water dissociation, and CO conversion, ultimately leading to high yields of C2+ products.

exo-6b2-Methyl-Substituted Pentabenzocorannulene: Synthesis, Structural Analysis, and Properties.

exo-6b2-Methyl-substituted pentabenzocorannulene (exoPBC-Me) was synthesized by the palladium-catalyzed cyclization of 1,2,3-triaryl-1H-cyclopenta[l]phenanthrene. Its bowl-shaped geometry with an sp3 carbon atom in the backbone and a methyl group located at the convex (exo) face was verified by X-ray crystallography. According to DFT calculations, the observed conformer is energetically more favorable than the endo one by 39.9 kcal/mol. Compared to the nitrogen-doped analogs with intact π-conjugated backbones (see the main text), exo-PBC-Me displayed a deeper bowl depth (avg. 1.93 Å), redshifted and broader absorption (250-620 nm) and emission (from 585 to more than 850 nm) bands and a smaller optical HOMO-LUMO gap (2.01 eV). exo-PBC-Me formed polar crystals where all bowl-in-bowl stacking with close π···π contacts is arranged unidirectionally, providing the potential for applications as organic semiconductors and pyroelectric materials. This unusual structural feature, molecular packing, and properties are most likely associated with the assistance of the methyl group and the sp3 carbon atom in the backbone.

Adjacent Copper Single Atoms Promote C-C Coupling in Electrochemical CO2 Reduction for the Efficient Conversion of Ethanol.

The electrochemical CO2 reduction reaction (CO2RR) using renewable electricity is one of the most promising strategies for reaching the goal of carbon neutrality. Multicarbonous (C2+) products have broad applications, and ethanol is a valuable chemical and fuel. Many Cu-based catalysts have been reported to be efficient for the electrocatalytic CO2RR to C2+ products, but they generally offer limited selectivity and current density toward ethanol. Herein, we proposed a silica-mediated hydrogen-bonded organic framework (HOF)-templated approach to preparing ultrahigh-density Cu single-atom catalysts (SACs) on thin-walled N-doped carbon nanotubes (TWN). The content of Cu in the catalysts prepared by this method could be up to 13.35 wt %. It was found that the catalysts showed outstanding performance for the electrochemical CO2RR to ethanol, and the Faradaic efficiency (FE) of ethanol increased with the increase in Cu-N3 site density. The FE of ethanol over the catalysts with 13.35 wt % Cu could reach ∼81.9% with a partial current density of 35.6 mA cm-2 using an H-type cell, which is the best result for electrochemical CO2RR to ethanol to date. In addition, the catalyst could be stably used for more than 25 h. Experimental and density functional theory (DFT) studies revealed that the adjacent Cu-N3 active sites (one Cu atom coordinates with three N) were the active sites for the reaction, and their high density was crucial for the high FE of ethanol because the adjacent Cu-N3 sites with a short distance could promote the C-C coupling synergistically.

Highly Distorted Multiple Helicenes: Syntheses, Structural Analyses, and Properties.

A series of hexapole helicenes (HHs) and nonuple helicenes (NHs) were prepared from 1,3,5-tris[2-(arylethynyl)phenyl]benzene through two steps, namely, iodocyclization and subsequent palladium-catalyzed annulation with ortho-bromoaryl carboxylic acids. The crucial advantages of this synthetic method are the facile introduction of substituents, high regioselectivity, and efficient backbone extension. Three-dimensional structures of three C1-symmetric HHs and one C3-symmetric NH were elucidated using X-ray crystallography. Unlike most conventional multiple helicenes, the HHs and NHs investigated herein possess a unique structural feature where some double helical moieties share a terminal naphthalene unit. Chiral resolution of a HH and an NH was successfully achieved, and the enantiomerization barrier (ΔH‡) of the HH was experimentally determined to be 31.2 kcal/mol. A straightforward method for predicting the most stable diastereomer was developed based on density functional theory calculations and structural considerations. It was found that the relative potential energies (ΔHrs) of all diastereomers for two HHs and one NH can be obtained using minimal computational effort to analyze the types, helical configurations, numbers, and ΔH(MP-MM)s [= H(M,P/P,M) - H(M,M/P,P)] of the double helicenyl fragments.

LongPhase: an ultra-fast chromosome-scale phasing algorithm for small and large variants.

MOTIVATION: Long-read phasing has been used for reconstructing diploid genomes, improving variant calling and resolving microbial strains in metagenomics. However, the phasing blocks of existing methods are broken by large Structural Variations (SVs), and the efficiency is unsatisfactory for population-scale phasing. RESULTS: This article presents a novel algorithm, LongPhase, which can simultaneously phase single nucleotide polymorphisms (SNPs) and SVs of a human genome in 10-20 min, 10× faster than the state-of-the-art WhatsHap, HapCUT2 and Margin. In particular, co-phasing SNPs and SVs produces much larger haplotype blocks (N50 = 25 Mbp) than those of existing methods (N50 = 10-15 Mbp). We show that LongPhase combined with Nanopore ultra-long reads is a cost-effective and highly contiguous solution, which can produce between one and 26 blocks per chromosome arm without the need for additional trios, chromosome-conformation and strand-seq data. AVAILABILITYAND IMPLEMENTATION: LongPhase is freely available at https://github.com/twolinin/LongPhase/. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Exosomes loading Tapasin enhance T cell immune response by autophagy to inhibit HBV replication.

Hepatitis B virus (HBV) specific T cell immune response plays a vital role in viral clearance. Dendritic cell derived exosomes (Dexs) can activate T cell immunity effectively. Tapasin (TPN) is involved in antigen processing and specific immune recognition. In the present study, we elucidated that Dexs loading TPN (TPN-Dexs) could enhance CD8+ T cell immune response and inhibit virus replication in HBV transgenic mice. T cell immune response and the ability of inhibiting HBV replication were measured in HBV transgenic mice immunized with TPN-Dexs. Meanwhile, CD8+ T cell autophagy and specific T cell immune responses were measured in vitro and vivo, and the mechanisms probably involved in were explored. Purified TPN-Dexs could be taken up into the cytoplasm of DCs and upregulate CD8+ T cell autophagy to enhance specific T cell immune response. In addition, TPN-Dexs could increase the expression of AKT and decrease the expression of mTOR in CD8+ T cells. Further research confirmed that TPN-Dexs could inhibit virus replication and decrease the expression of HBsAg in the liver of HBV transgenic mice. Nevertheless, those also could elicit mice hepatocytes damage. In conclusion, TPN-Dexs could enhance specific CD8+ T cell immune responses via the AKT/mTOR pathway to regulate the autophagy and exert the antiviral effect in HBV transgenic mice.

Associations between urinary caffeine and caffeine metabolites and cognitive function in older adults.

BACKGROUND: The effects of caffeine on cognitive impairment have not been conclusively determined. This study aimed to objectively assess the correlation between the urinary caffeine and caffeine metabolites and cognitive decline in older adults. METHODS: Data on urinary caffeine and caffeine metabolites and the cognitive performance of participants aged 60 years and older were extracted from the National Health and Nutrition Examination Surveys 2011-2014. Binary logistic regression and restricted cubic splines (RCS) analyses were used to evaluate the association between urinary caffeine and caffeine metabolites and cognitive performance. RESULTS: Eight hundred twenty-seven individuals were enrolled in this cross-sectional study. We observed that 1-methylxanthine, 3-methylxanthine, 7-methylxanthine, 1,3-dimethylxanthine, 1,7-dimethylxanthine, and 3,7-dimethylxanthine levels were significantly and inversely associated with cognitive decline. The RCS results suggested an approximately linear dose-response relationship between the aforementioned metabolites and cognitive performance. Moreover, the effects of urinary caffeine and caffeine metabolites on cognitive function assessed using the AFT were more evident in men. CONCLUSIONS: Our study suggested that urinary caffeine and caffeine metabolite levels were associated with a reduced risk of cognitive impairment in a linear manner, especially in men.

Functional connectivity analysis on electroencephalography signals reveals potential biomarkers for treatment response in major depression.

BACKGROUND: The treatment efficacy varies across individual patients with major depressive disorder (MDD). It lacks robust electroencephalography (EEG) markers for an antidepressant-responsive phenotype. METHOD: This is an observational study enrolling 28 patients with MDD and 33 healthy controls (mean age of 40.7 years, and 71.4% were women). Patients underwent EEG exams at baseline (week0) and week1, while controls' EEG recordings were acquired only at week0. A resting eye-closing EEG segment was analyzed for functional connectivity (FC). Four parameters were used in FC analysis: (1) node strength (NS), (2) global efficiency (GE), (3) clustering coefficient (CC), and (4) betweenness centrality (BC). RESULTS: We found that controls had higher values in delta wave in the indices of NS, GE, BC, and CC than MDD patients at baseline. After treatment with antidepressants, patients' FC indices improved significantly, including GE, mean CC, and mean NS in the delta wave. The FC in the alpha and beta bands of the responders were higher than those of the non-responders. CONCLUSIONS: The FC of the MDD patients at baseline without treatment was worse than that of controls. After treatment, the FC improved and was close to the values of controls. Responders showed better FC in the high-frequency bands than non-responders, and this feature exists in both pre-treatment and post-treatment EEG.

Clear cell carcinoma arising in an ovarian remnant 19 years after oophoerctomy: case report.

BACKGROUND: Ovarian remnant syndrome (ORS) is a rare complication that occurs after oophorectomy, characterized by residual ovarian tissue causing pelvic pain, masses, and various symptoms. The clinical manifestations of ORS are nonspecific, and its diagnosis relies on histological examination. Since ORS typically represents a benign ovarian lesion, there have been few reported cases of malignant transformation. In this report, we presented a unique case of ovarian clear cell carcinoma (OCCC) arising from an ovarian remnant following salpingo-oophorectomy. CASE PRESENTATION: Our patient was a 47-year-old female initially diagnosed with uterine myoma. She had previously undergone cesarean section and unilateral salpingo-oophorectomy. Transvaginal ultrasound and computed tomography (CT) scans revealed a soft tissue mass adjacent to the right lateral wall of the myometrium. The patient opted for transabdominal hysterectomy, left adnexal resection, laparoscopic omentectomy, appendectomy, and pelvic and abdominal lymphadenectomy. The final pathology results confirmed the diagnosis of OCCC, consistent with ORS. The patient subsequently received six cycles of intravenous chemotherapy using the carboplatin/paclitaxel (TC) regimen (paclitaxel liposomes 175 mg/m², carboplatin AUC 5). After 3 years of follow-up, the patient's condition remained normal. CONCLUSION: ORS can significantly impact patients' quality of life and pose challenges for clinicians. Complete excision of ovarian tissue during the initial surgery is crucial in preventing ORS recurrence and potential malignant transformation of ovarian remnants.

A Short-Time Real-World Study of Two Perfluoropropane Tamponade Methods in Pars Plana Vitrectomy for Retinal Detachment.

INTRODUCTION: This real-world study evaluated the efficacy, safety, and operative parameters of two perfluoropropane (C3F8) tamponade methods combined with pars plana vitrectomy (PPV) for retinal detachment (RD). METHODS: A retrospective study of 132 patients (132 eyes) with RD (pure C3F8 in 38 eyes, mixed C3F8 in 94 eyes). All eyes underwent PPV with C3F8 tamponade and were followed up for at least 3 months. Retinal reattachment rate, time of gas configuration and injection, C3F8 dosage, intraocular pressure (IOP), best corrected visual acuity, postoperative ocular inflammation, and patients' complaints were evaluated. RESULTS: The single-surgery retinal reattachment rates of the pure C3F8 group and mixed C3F8 group were 97.4% and 96.8%, respectively, with no significant difference (p = 1.00). The final retinal reattachment rates of the two groups were 100% and 97.2%, respectively, with no significant difference (p = 1.00). The gas configuration time, gas injection time, and C3F8 dosage were significantly less in the pure C3F8 group (all p < 0.001). Time, but not group, was the influencing factor of postoperative IOP changes in the two groups (p < 0.001, p = 0.547, respectively). Compared with the baseline, the IOP estimates of the pure C3F8 group showed a significant increase immediately after surgery (p < 0.001), and the mixed C3F8 group showed a significant increase immediately and 1-2 days after surgery (all p < 0.05). There was no statistical difference in ocular inflammation (p = 0.339) and patients' complaints of discomfort (p = 0.175) between the two groups. CONCLUSION: Both the two methods of C3F8 tamponade combined with PPV in RD patients showed good efficacy and safety, but the clinical operation of pure C3F8 tamponade was more convenient and eco-friendly.

Promoting Heme and Phycocyanin Biosynthesis in Synechocystis sp. PCC 6803 by Overexpression of Porphyrin Pathway Genes with Genetic Engineering.

Due to their unique biochemical and spectroscopic properties, both heme and phycocyanobilin are widely applied in the medical and food industries. Synechocystis sp. PCC 6803 contains both heme and phycocyanin, and is capable of synthesizing phycocyanin using heme as a precursor. The aim of this study was to uncover viable metabolic targets in the porphyrin pathway from Synechocystis sp. PCC 6803 to promote the accumulation of heme and phycocyanin in the recombinant strains of microalgae. A total of 10 genes related to heme synthesis pathway derived from Synechococcus elongatus PCC 7942 and 12 genes related to endogenous heme synthesis were individually overexpressed in strain PCC 6803. The growth rate and pigment content (heme, phycocyanin, chlorophyll a and carotenoids) of 22 recombinant algal strains were characterized. Quantitative real-time PCR technology was used to investigate the molecular mechanisms underlying the changes in physiological indicators in the recombinant algal strains. Among the 22 mutant strains, the mutant overexpressing the haemoglobin gene (glbN) of strain PCC 6803 had the highest heme content, which was 2.5 times higher than the wild type; the mutant overexpressing the gene of strain PCC 7942 (hemF) had the highest phycocyanin content, which was 4.57 times higher than the wild type. Overall, the results suggest that genes in the porphyrin pathway could significantly affect the heme and phycocyanin content in strain PCC 6803. Our study provides novel crucial targets for promoting the accumulation of heme and phycocyanin in cyanobacteria.

Differences of the anti-oxidative capability, GPX3, and Cu/ZnSOD expression in Hu sheep testis with different size at six-month-old.

This study aimed to investigate the differences in the anti-oxidant capabilities and related gene expressions of six-month-old Hu sheep with different testis sizes. A total of 201 Hu ram lambs were fed up to 6 months in the same environment. Based on their testis weight and sperm count, 18 individuals were selected and divided into large (n = 9) and small (n = 9) groups, with an average testis weight of 158.67 g ± 5.21 g and 44.58 g ± 4.14 g, respectively. The total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD), and malondialdehyde (MDA) concentration in testis tissue were tested. The localization of antioxidant-related genes, GPX3 and Cu/ZnSOD in testis were detected by immunohistochemistry. The GPX3, Cu/ZnSOD expression, and relative mitochondrial DNA (mtDNA) copy number were detected by quantitative real-time PCR. Compared with the small group, the T-AOC (2.69 ± 0.47 vs. 1.16 ± 0.22 U/mgprot) and T-SOD (22.35 ± 2.59 vs. 9.92 ± 1.62 U/mgprot) in the large group were significantly higher, whereas the MDA (0.72 ± 0.13 vs. 1.34 ± 0.17 nM/mgprot) and relative mtDNA copy number in the large group was significantly lower (p < .05). Immunohistochemistry results indicated that the GPX3 and Cu/ZnSOD were expressed in Leydig cells and seminiferous tubule. The expressions of GPX3 and Cu/ZnSOD mRNA in the large group were significantly higher than those in the small group (p < .05). In conclusion, Cu/ZnSOD and GPX3 widely expressed in the Leydig cells and seminiferous tubule, high expression of Cu/ZnSOD and GPX3 in a large group has a higher potential in addressing oxidative stress and contribute to spermatogenesis.

Structural transitions of centromeric chromatin regulate the cell cycle-dependent recruitment of CENP-N.

Specific recognition of centromere-specific histone variant CENP-A-containing chromatin by CENP-N is an essential process in the assembly of the kinetochore complex at centromeres prior to mammalian cell division. However, the mechanisms of CENP-N recruitment to centromeres/kinetochores remain unknown. Here, we show that a CENP-A-specific RG loop (Arg80/Gly81) plays an essential and dual regulatory role in this process. The RG loop assists the formation of a compact "ladder-like" structure of CENP-A chromatin, concealing the loop and thus impairing its role in recruiting CENP-N. Upon G1/S-phase transition, however, centromeric chromatin switches from the compact to an open state, enabling the now exposed RG loop to recruit CENP-N prior to cell division. Our results provide the first insights into the mechanisms by which the recruitment of CENP-N is regulated by the structural transitions between compaction and relaxation of centromeric chromatin during the cell cycle.