Kukoamine A alleviates nephrolithiasis by inhibiting endogenous oxalate synthesis via the IL-6/JAK/STAT3/DAO signaling pathway.

BACKGROUND: The recurrent nature and socioeconomic burden of nephrolithiasis demand effective treatments. Delineating the crosstalk between inflammatory processes and the endogenous oxalate metabolism pathway, which underpins nephrolithiasis pathogenesis, is essential for advancing treatment strategies. PURPOSE: We aim to screen therapeutic Chinese herbal remedies and their bioactive constituents for kidney stone treatment using a fruit fly model, followed by efficacy and mechanism validation in a rodent nephrolithiasis model as well as in vitro human cell culture model. STUDY DESIGN AND METHODS: We developed a fruit fly model to screen for efficient traditional Chinese medicine herbs and their active compounds for kidney stone treatment. Candidate active compounds from efficient herbs were separated and identified by solid-phase chromatography coupled with LC-MS analysis. Fruit fly genetic tools were employed to manipulate the expression of related genes to explore the therapeutic mechanisms of the Lycii Cortex and kukoamine A (KuA). To confirm the therapeutic effects and mechanisms of KuA for mammalian nephrolithiasis, mouse model of glyoxylate-induced kidney stone and human renal tubular cells were used. The therapeutic role of kukoamine A in nephrolithiasis was evaluated by assessing tubular injury, crystal deposition, and adhesion. The level of expression and phosphorylation in cells and mice was assessed using RT-qPCR and western blot. RESULTS: Our findings indicate that Lycii Cortex potently inhibits calcium oxalate stone formation via activation of the JNK/Upd3/JAK/STAT signaling cascade, resulting in diminished endogenous oxalate synthesis by downregulating D-amino acid oxidase (DAO) gene expression, predominantly in fruit fly Malpighian tube stellate cells. KuA was identified as the principal bioactive constituent mediating these effects. Both mouse models and human cell assays confirmed KuA's efficacy in preventing calcium oxalate nephrolithiasis in mammals, through hepatic JAK/STAT3 pathway activation and upregulation of IL-6, culminating in reduced urinary crystal deposition. CONCLUSION: Our research underscores the potential of kukoamine A as a lead compound in treating nephrolithiasis and reveals the interplay between the IL-6/JAK/STAT3 inflammatory pathway and endogenous oxalate metabolism in nephrolithiasis pathogenesis. Additionally, it highlights the utility of the fruit fly model as a powerful tool for deciphering the therapeutic mechanisms of traditional Chinese herbs.

The Different Concentrations of Applied Exogenous Sugars Widely Influence the Specificity, Significance and Physiological Relevance of Study Outcomings.

Plant growth and development are governed via signal networks that connect inputs from nutrient status, hormone signals, and environmental cues. Substantial researches have indicated a pivotal role of sugars as signalling molecules in plants that integrate external environmental cues and other nutrients with intrinsic developmental programmes regulated via multiple plant hormones. Therefore, plant growth and development are controlled through complication signalling networks. However, in many studies, to obtain more obviously experimental findings, excess concentrations of applied exogenous sugars have aggravated the complexity of this signalling networks. Once researchers underestimate this complexity, a series of contradictory or contrasting findings will be generated. More importantly, in terms of these contradictory findings, more contradictory study outcomings are derived. In this review, we carefully analyze some reports, and find that these reports have confused or neglected that the sugar-antagonism of ethylene signalling is specific or conditional. As a result, many contradictory conclusions are generated, which will in turn misdirect the scientific community.

Electrochemical deconstruction of alkyl substituted boron clusters to produce alkyl boronate esters.

Closo-Hexaborate (closo-B6H62-) can engage in nucleophilic substitution reactions with a wide variety of alkyl electrophiles. The resulting functionalized boron clusters undergo oxidative electrochemical deconstruction, selectively cleaving B-B bonds while preserving B-C bonds in these species. This approach allows the conversion of multinuclear boron clusters into single boron site organoboranes. Trapped boron-based fragments were isolated from the electrochemical cluster deconstruction process, providing further mechanistic insights into the developed reaction.

Preparation and Properties of Lightweight Aggregates from Discarded Al2O3-ZrO2-C Refractories.

Refractory materials are an important pillar for the stable development of the high-temperature industry. A large amount of waste refractories needs to be further disposed of every year, so it is of great significance to carry out research on the recycling of used refractories. In this work, lightweight composite aggregate was prepared by using discarded Al2O3-ZrO2-C refractories as the main raw material, and the performance of the prepared lightweight aggregate was improved by adjusting the calcination temperature and introducing light calcined magnesia additives. The results showed that the cold compressive strength and thermal shock resistance of the lightweight aggregates were significantly improved with increasing calcination temperature. Moreover, the introduction of light calcined magnesia can effectively improve the apparent porosity, cold compressive strength, and thermal shock resistance of the prepared lightweight aggregates at the calcination temperature of 1400 °C. Consequently, this work provides a useful reference for the resource utilization of used refractories, while the prepared lightweight aggregates are expected to be applied in the field of high-temperature insulation.

[Evaluation of the role of standardized periodontal probing training on the teaching of undergraduates using the Florida probe system].

PURPOSE: To evaluate the effect of standardized periodontal probing training on the teaching of periodontal clinical probing for undergraduates by using Florida probe system. METHODS: Twenty undergraduates who practiced in the Department of Periodontology of Changzhou Stomatological Hospital from May 2022 to November 2022 were selected as the study objects and randomly divided into two groups with 10 students in each group. The experimental group received standardized periodontal probing training, while the control group did not receive training. Two groups of students used the traditional probe and the Florida probe to probe the left and right half-mouth teeth of one patient. In addition, a periodontal specialist used Florida probe to conduct full oral examination of the same patient, and the results were compared with those of the two groups of students. SPSS 26.0 software package was used for statistical analysis of the obtained data. RESULTS: There was no significant difference of probing depth(PD) between undergraduates and periodontal specialist in the experimental group (P＞0.05), while there was significant difference in the control group (P＜0.05). In the control group, PD values in the anterior area were not statistically different from those of periodontal specialist (P＞0.05), while PD values in the posterior area were statistically different (P＜0.05). Both groups of patients reported that the Florida probe system was more comfortable. CONCLUSIONS: Standardized periodontal probing training is helpful to improve the clinical probing ability of undergraduates. The use of Florida probe system can not only evaluate the teaching effect, but also improve the comfort level of patients, which is worthy of further application in the teaching course of periodontal probing for undergraduates.

A visualized and bibliometric analysis of nursing research during the COVID-19 pandemic.

BACKGROUND: The global spread of Coronavirus disease 2019 (COVID-19) has been increasing since December 2019. A total of 8460 publications were obtained from the Web of Science Core Collection from 2019 to 2023, providing insights into the progress of nursing research throughout the COVID-19 pandemic. METHODS: Bibliometric analysis was conducted on these articles using CiteSpace. The analysis focused on examining the distribution of these publications in terms of space and time, distribution of authors, subject categories, distribution of topics, and cited references. RESULTS: These results may be explained from 3 perspectives. Initially, the number of yearly publications on nursing research consistently increased during the COVID-19 pandemic. Furthermore, a co-occurrence analysis of the countries and the authors revealed that certain countries, including the United States, China, and England, have successfully implemented organized and standardized nursing models. These countries also have well-developed and established nursing research systems. Notably, academic communities in specific regions, such as the team led by MD Stefan Gravenstein, Mor Vincent, and White Elizabeth at Brown University in the United States, have emerged as leaders in this field. Furthermore, examining the papers' subject categories and topic distribution indicate that nursing during the COVID-19 pandemic has been predominantly interdisciplinary, encompassing various disciplines such as clinical medicine, essential medicine, psychology, public health management, and even telematics science. CONCLUSION SUBSECTIONGS: Our study provided valuable insights into acquiring knowledge on nursing research during the COVID-19 pandemic, pinpointed possible partners for researchers interested in nursing, and uncovered prevalent research patterns and popular subjects.

Epidemiological features and temporal trends of the co-infection between HIV and tuberculosis, 1990-2021: findings from the Global Burden of Disease Study 2021.

BACKGROUND: The co-infection of human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) and tuberculosis (TB) poses a significant clinical challenge and is a major global public health issue. This study aims to elucidate the disease burden of HIV-TB co-infection in global, regions and countries, providing critical information for policy decisions to curb the HIV-TB epidemic. METHODS: The ecological time-series study used data from the Global Burden of Disease (GBD) Study 2021. The data encompass the numbers of incidence, prevalence, mortality, and disability-adjusted life year (DALY), as well as age-standardized incidence rate (ASIR), prevalence rate (ASPR), mortality rate (ASMR), and DALY rate for HIV-infected drug-susceptible tuberculosis (HIV-DS-TB), HIV-infected multidrug-resistant tuberculosis (HIV-MDR-TB), and HIV-infected extensively drug-resistant tuberculosis (HIV-XDR-TB) from 1990 to 2021. from 1990 to 2021. The estimated annual percentage change (EAPC) of rates, with 95% confidence intervals (CIs), was calculated. RESULTS: In 2021, the global ASIR for HIV-DS-TB was 11.59 per 100,000 population (95% UI: 0.37-13.05 per 100,000 population), 0.55 per 100,000 population (95% UI: 0.38-0.81 per 100,000 population), for HIV-MDR-TB, and 0.02 per 100,000 population (95% UI: 0.01-0.03 per 100,000 population) for HIV-XDR-TB. The EAPC for the ASIR of HIV-MDR-TB and HIV-XDR-TB from 1990 to 2021 were 4.71 (95% CI: 1.92-7.59) and 13.63 (95% CI: 9.44-18.01), respectively. The global ASMR for HIV-DS-TB was 2.22 per 100,000 population (95% UI: 1.73-2.74 per 100,000 population), 0.21 per 100,000 population (95% UI: 0.09-0.39 per 100,000 population) for HIV-MDR-TB, and 0.01 per 100,000 population (95% UI: 0.00-0.03 per 100,000 population) for HIV-XDR-TB in 2021. The EAPC for the ASMR of HIV-MDR-TB and HIV-XDR-TB from 1990 to 2021 were 4.78 (95% CI: 1.32-8.32) and 10.00 (95% CI: 6.09-14.05), respectively. CONCLUSIONS: The findings indicate that enhancing diagnostic and treatment strategies, strengthening healthcare infrastructure, increasing access to quality medical care, and improving public health education are essential to combat HIV-TB co-infection.

Patent ductus arteriosus and the association between lung ultrasound score and bronchopulmonary dysplasia: a secondary analysis of a prospective study.

Moderate-to-large patent ductus arteriosus (PDA) has been linked to increased risk of bronchopulmonary dysplasia (BPD), while lung ultrasound score (LUS) has been demonstrated to accurately predict BPD. We aimed to investigate the correlation of LUS as a marker of interstitial pulmonary edema and the severity of the ductal shunt in predicting future BPD development in very preterm infants. This secondary analysis of a prospective study recruited preterm infants with gestational age < 30 weeks. LUS on postnatal days 7 and 14, and echocardiographic data [PDA diameter and left atrium-to-aortic root ratio (LA/Ao)] near LUS acquisition were collected. Correlation coefficient, logistics regression analysis, and the area under the receiver operating characteristic (AUROC) procedure were used. A statistically significant and positive correlation existed between LUS and PDA diameter (ρ = 0.415, ρ = 0.581, and p < 0.001) and LA/Ao (ρ = 0.502, ρ = 0.743, and p < 0.001) at postnatal days 7 and 14, respectively, and the correlations of LUS and echocardiographic data were generally stronger in the non-BPD group. In the prediction of BPD, LUS incorporating echocardiographic data at postnatal days 7 obtained significantly higher predictive performance compared to LUS alone (AUROC 0.878 [95% CI 0.801-0.932] vs. AUROC 0.793 [95% CI 0.706-0.865]; Delong test, p = 0.013). CONCLUSIONS: There is a statistically significant correlation between LUS and echocardiographic data, suggesting their potential role as early predictors for respiratory outcomes in very preterm infants. WHAT IS KNOWN: • Lung ultrasound score (LUS) has shown good reliability in predicting bronchopulmonary dysplasia (BPD) development. • Some echocardiographic data that characterized ventricular function was reported to be used to predict severe BPD. WHAT IS NEW: • There is a positive and statistically significant correlation between LUS and echocardiographic data at postnatal days 7 and 14. • The integrated use of LUS and echocardiographic data may have potential value in predicting BPD.

Knowledge, attitudes and practices toward cervical cancer screening among ethnic minorities in inner Mongolia, China.

AIMS: This study aimed to assess the knowledge, attitudes and practices (KAP) towards cervical cancer screening among ethnic minorities in Inner Mongolia, China. METHODS: A cross-sectional study was conducted in Inner Mongolia between May and September, 2023, and recruiting participants undergoing dual-cancer screening. Demographic characteristics and KAP status were assessed using a self-administered questionnaire. RESULTS: A total of 533 valid questionnaires were collected, with 53.66% aged 40 years or younger. Mean scores for knowledge, attitude, and practice were 13.58 ± 5.41, 41.06 ± 4.53, and 13.35 ± 1.53, respectively. Positive associations were found between knowledge and attitude (r = 0.348, p < 0.001), knowledge and practice (r = 0.288, p < 0.001), and attitude and practice (r = 0.817, p < 0.001). Structural equation modelling confirmed direct positive associations between knowledge and attitude (path coefficient = 0.307, p < 0.001) and attitude and practice (path coefficient = 0.270, p < 0.001). Additionally, knowledge demonstrated an indirectly positive association with practice (path coefficient = 0.083, p = 0.007). CONCLUSION: Ethnic minorities in Inner Mongolia exhibit insufficient knowledge, positive attitudes, and proactive practices toward cervical cancer screening. Implementing targeted educational initiatives is crucial to enhance their KAP.

A Pd-catalyzed route to carborane-fused boron heterocycles.

Due to the expanding applications of icosahedral carboranes in medicinal and materials chemistry research, their functionalizations have become one of the central themes in boron-rich cluster chemistry. Although several strategies for incorporating nitrogen-containing nucleophiles on a single boron vertex of the icosahedral carboranes (C2B10H12) have been developed, methods for preparing clusters with vicinal B-N moieties are still lacking. The steric bulk of icosahedral carboranes and disparate electronic and steric nature of the N-containing groups have rendered the vicinal diamination challenging. In this article, we show how a developed Pd-catalyzed process is used to incorporate an array of NH-heterocycles, anilines, and heteroanilines with various electronic and steric profiles onto the vicinal boron vertices of a meta-carborane cluster via sequential or one-pot fashion. Importantly, oxidative cyclizations of the cross-coupling products with indoles and pyrroles appended to boron vertices generate a previously unknown class of all-boron-vertex bound carborane-fused six- and seven-membered ring heterocycles. Photophysical studies of the meta-carborane-fused heterocycles show that these structures can exhibit luminescence with high quantum yields and are amenable to further manipulations.

Hearing loss is not associated with risk of Parkinson's disease: A Mendelian randomization study.

Purpose: A few observational studies have indicated that Parkinson's disease (PD) risk may be higher in those with hearing loss, but the two's causal relationship is yet unknown. Using Mendelian randomization (MR) methods, this study sought to explore the causal link between hearing loss and the risk of PD. Methods: We identified single nucleotide polymorphisms (SNPs) linked to hearing loss (P-value<5E-08) in a genome-wide association study (GWAS) included 323,978 people from the UK Biobank. The summary data for PD in the discovery group came from a GWAS meta-analysis of 33,647 cases and 449,056 healthy participants of European descent. Using summary data from the aforementioned GWAS of PD (N = 33,647) and hearing loss (N = 323,978), we carried out a two-sample MR study. As validation groups, two separate PD GWAS studies were used. Inverse variance weighting (IVW) was utilized in the principal MR analysis. For our findings to be reliable, further analyses were carried out with the Cochran's Q test, MR-Egger intercept, and leave-one-out analysis. In addition, we assessed the causal link between various forms of hearing loss and PD using the IVW approach. Results: Twenty-two SNPs with genome-wide significance linked to hearing loss were used as instrumental factors. In the discovery dataset, we failed to detect a causal relationship between hearing loss and PD (OR = 1.297; 95 % CI = 0.420-4.007; P-value = 0.651). The findings of other methods agreed with the IVW method. The results were robust under sensitivity analyses. Furthermore, the above findings were confirmed in two validation PD datasets. Additionally, no causal correlation was found between genetic prediction of four different types of hearing loss and PD (conductive hearing loss, IVW: OR = 1.058, 95%CI = 0.988-1.133, P-value = 0.108; sudden idiopathic hearing loss, IVW: OR = 0.936, 95%CI = 0.863-1.016, P-value = 0.113; mixed conductive and sensorineural hearing loss, IVW: OR = 0.963, 95%CI = 0.878-1.058, P-value = 0.436; sensorineural hearing loss, IVW: OR = 1.050, 95%CI = 0.948-1.161, P-value = 0.354). Conclusion: In those of European heritage, our investigation revealed no causal link between hearing loss and PD risk.

Metagenomic analysis revealed the association between gut microbiota and different ovary responses to controlled ovarian stimulation.

The aim of this study was to assess the correlation between gut microbial taxonomy and various ovarian responses to controlled ovarian stimulation. A total of 22 IVF cycles with a follicle-to-oocyte index (FOI) < 0.5 and 25 IVF cycles with FOI ≥ 0.5 were included in this study. Baseline demographic characteristics were compared between the two groups. Metagenomic sequencing was performed to analyze fecal microbial community profiles. Mice were used to evaluate the effect of Bifidobacterium_longum on ovarian response to stimulation. Compared with FOI < 0.5 group, women in group with FOI ≥ 0.5 had significant more oocytes retrieved (p < 0.01). Prevotella_copri, Bateroides_vulgatus, Escherichia_coli and Bateroides_stercoris were more abundant in FOI < 0.5 group while Bifidobacterium_longum, Faecalibacterium_prausnitzii, Ruminococcus_gnavus and Bifidobacterium_pseudocatenula were more abundant in FOI ≥ 0.5 group. After adjusting for women's age and BMI, Pearson correlation analysis indicated alteration of gut microbiome was related with serum E2, FSH, number of oocytes retrieved and clinical pregnancy rate. Animal study showed ovarian response will be improved after Bifidobacterium_longum applied. An increased abundance of Bacteroidetes and Prevotella copri, as well as a decreased abundance of Bifidobacterium longum, have been found to be associated with poor ovarian responsiveness. Changes in gut microbiomes have been observed to be correlated with certain clinical characteristics. The potential enhancement of ovarian response may be facilitated by the integration of Bifidobacterium longum.

Total Synthesis of Strigolactones via Palladium-Catalyzed Cascade Carbonylative Carbocyclization of Enallenes.

Here we report an efficient route for synthesizing strigolactones (SLs) and their derivatives. Our method relies on a palladium-catalyzed oxidative carbonylation/carbocyclization/carbonylation/alkoxylation cascade reaction, which involves the formation of three new C-C bonds and a new C-O bond while cleaving one C(sp3)-H bond in a single step. With our versatile synthetic strategy, both naturally occurring and artificial SLs were prepared.

The LysR family transcriptional regulator ORF-L16 regulates spinosad biosynthesis in Saccharopolyspora spinosa.

Spinosad, a potent broad-spectrum bioinsecticide produced by Saccharopolyspora spinosa, has significant market potential. Despite its effectiveness, the regulatory mechanisms of spinosad biosynthesis remain unclear. Our investigation identified the crucial role of the LysR family transcriptional regulator ORF-L16, located upstream of spinosad biosynthetic genes, in spinosad biosynthesis. Through reverse transcription PCR (RT-PCR) and 5'-rapid amplification of cDNA ends (5'-Race), we unveiled that the spinosad biosynthetic gene cluster (BGC) contains six transcription units and seven promoters. Electrophoretic mobility shift assays (EMSAs) demonstrated that ORF-L16 bound to seven promoters within the spinosad BGC, indicating its involvement in regulating spinosad biosynthesis. Notably, deletion of ORF-L16 led to a drastic reduction in spinosad production from 1818.73 mg/L to 1.69 mg/L, accompanied by decreased transcription levels of spinosad biosynthetic genes, confirming its positive regulatory function. Additionally, isothermal titration calorimetry (ITC) and EMSA confirmed that spinosyn A, the main product of the spinosad BGC, served as an effector of ORF-L16. Specifically, it decreased the binding affinity between ORF-L16 and spinosad BGC promoters, thus exerting negative feedback regulation on spinosad biosynthesis. This research enhances our comprehension of spinosad biosynthesis regulation and lays the groundwork for future investigations on transcriptional regulators in S. spinosa.

In-situ noncovalent interaction of ammonium ion enabled C-H bond functionalization of polyethylene glycols.

The noncovalent interactions of ammonium ion with multidentate oxygen-based host has never been reported as a reacting center in catalytic reactions. In this work, we report a reactivity enhancement process enabled by non-covalent interaction of ammonium ion, achieving the C-H functionalization of polyethylene glycols with acrylates by utilizing photoinduced co-catalysis of iridium and quinuclidine. A broad scope of alkenes can be tolerated without observing significant degradation. Moreover, this cyano-free condition respectively allows the incorporation of bioactive molecules and the PEGylation of dithiothreitol-treated bovine serum albumin, showing great potentials in drug delivery and protein modification. DFT calculations disclose that the formed α-carbon radical adjacent to oxygen-atom is reduced directly by iridium before acrylate addition. And preliminary mechanistic experiments reveal that the noncovalent interaction of PEG chain with the formed quinuclidinium species plays a unique role as a catalytic site by facilitating the proton transfer and ultimately enabling the transformation efficiently.

Isolated hepatic sarcoidosis: A case series.

Sarcoidosis is a multi-organ inflammatory disease that can have hepatic involvement in up to 80% of cases. Rarely, sarcoidosis can manifest with only confined disease to the liver. While most patients with hepatic sarcoidosis are clinically silent, certain cases can have insidious onset leading to cirrhosis and secondary complications. Here, we describe three cases of isolated hepatic sarcoidosis to illustrate the range of presentations that may be associated with this condition. Clinicians should be vigilant in consideration of hepatic sarcoidosis as a culprit when investigating patients with undifferentiated liver disease.

Development of wafer-scale multifunctional nanophotonic neural probes for brain activity mapping.

Optical techniques, such as optogenetic stimulation and functional fluorescence imaging, have been revolutionary for neuroscience by enabling neural circuit analysis with cell-type specificity. To probe deep brain regions, implantable light sources are crucial. Silicon photonics, commonly used for data communications, shows great promise in creating implantable devices with complex optical systems in a compact form factor compatible with high volume manufacturing practices. This article reviews recent developments of wafer-scale multifunctional nanophotonic neural probes. The probes can be realized on 200 or 300 mm wafers in commercial foundries and integrate light emitters for photostimulation, microelectrodes for electrophysiological recording, and microfluidic channels for chemical delivery and sampling. By integrating active optical devices to the probes, denser emitter arrays, enhanced on-chip biosensing, and increased ease of use may be realized. Silicon photonics technology makes possible highly versatile implantable neural probes that can transform neuroscience experiments.

NIR-driven multifunctional PEC biosensor based on aptamer-modified PDA/MnO2 photoelectrode for bacterial detection and inactivation.

Sensitive detection and effective inactivation of bacteria are essential in preventing foodborne bacterial infection that poses a significant threat to human health. Herein, a near-infrared (NIR)-driven multifunctional photoelectrochemical (PEC) biosensor was constructed for detection and inactivation of S. aureus. Based on the covalent bonding between amine and carboxyl groups, carboxyl-functionalized SA31 aptamer was immobilized on the PDA/MnO2 photoelectrode. In the presence of S. aureus, SA31 aptamer can specifically capture S. aureus, causing the decrease of photocurrent signal owing to steric hindrance effect. Leveraging photocurrent-off signal, there existed a satisfied linear relationship between the photocurrent variation and the logarithm of S. aureus concentration, achieving a wide linear range from 10 to 107 CFU/mL with a low detection limit of 2.0 CFU/mL. Notably, PDA/MnO2 with peroxidase-like activity facilitated the catalytic oxidation of S. aureus with assistance of hydrogen peroxide (H2O2) to cause the inactivation of S. aureus. Desorption of inactivated S. aureus from the photoelectrode led to a recovery of photocurrent signal, enabling a "signal on" switch. Simultaneously, the excellent photothermal performance of the PDA/MnO2 converted light energy into heat energy under the irradiation of NIR light (808 nm, 1.5 W/cm2), triggering the synergistic antibacterial effect against S. aureus (97.36%). This work provides a novel strategy for fabricating the detection and inactivation of bacteria in practical applications.

1D Cu(I)-based chiral organic-inorganic hybrid material with second harmonic generation and circular polarized luminescence.

In recent years, organic-inorganic hybrid materials have demonstrated exceptional performance in nonlinear optics, attracting widespread attention. However, there are relatively few examples of coordination compounds synthesized with Cu as the metal center that exhibit excellent nonlinear optical properties. In this study, we successfully synthesized a pair of enantiomers named R/S-Cu2I2 by reacting chiral ligands with CuI. The crystal structure reveals a one-dimensional copper-iodide chain structure built by Cu2I2 clusters, and its ordered arrangement in space provides not only a strong second harmonic generation (SHG) signal (1.24 × KDP) but also a large birefringence (0.15@1064 nm). Under excitation at 395 nm, the crystals exhibit red fluorescence peaked at 675 nm. The CD spectra of R/S-Cu2I2 show a distinct mirror-symmetric Cotton effect, and their CPL signals are corresponding and opposite in the emission range, with a maximum glum of approximately ±2.5 × 10-3. Theoretical calculations using density functional theory were also carried out to enhance our understanding of the correlation between their structures and optical properties.

Exercise-induced calf muscle hyperemia quantified with dynamic blood oxygen level-dependent (BOLD) imaging.

Muscle hyperemia in exercise is usually the combined result of increased cardiac output and local muscle vasodilation, with the latter reflecting muscle's capacity for increased blood perfusion to support exercise. In this study, we aim to quantify muscle's vasodilation capability with dynamic BOLD imaging. A deoxyhemoglobin-kinetics model is proposed to analyze dynamic BOLD signals acquired during exercise recovery, deriving a hyperemia index (HI) for a muscle group of interest. We demonstrated the method's validity with calf muscles of healthy subjects who performed plantar flexion for muscle stimulation. In a test with exercise load incrementally increasing from 0 to 16 lbs., gastrocnemius HI showed considerable variance among the 4 subjects, but with a consistent trend, i.e. low at light load (e.g. 0-6 lbs) and linearly increasing at heavy load. The high variability among different subjects was confirmed with the other 10 subjects who exercised with a same moderate load of 8 lbs., with coefficient of variance among subjects' medial gastrocnemius 87.8%, lateral gastrocnemius 111.8% and soleus 132.3%. These findings align with the fact that intensive exercise induces high muscle hyperemia, but a comparison among different subjects is hard to make, presumably due to the subjects' different rate of oxygen utilization. For the same 10 subjects who exercised with load of 8 lbs., we also performed dynamic contrast enhanced (DCE) MRI to measure muscle perfusion (F). With a moderate correlation of 0.654, HI and F displayed three distinctive responses of calf muscles: soleus of all the subjects were in the cluster of low F and low HI, and gastrocnemius of most subjects had high F and either low or high HI. This finding suggests that parameter F encapsulates blood flow through vessels of all sizes, but BOLD-derived HI focuses on capillary flow and therefore is a more specific indicator of muscle vasodilation. In conclusion, the proposed hyperemia index has the potential of quantitatively assessing muscle vasodilation induced with exercise.