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1.
Brain ; 2024 May 13.
Article in English | MEDLINE | ID: mdl-38739753

ABSTRACT

Human brain organoids represent a remarkable platform for modeling neurological disorders and a promising brain repair approach. However, the effects of physical stimulation on their development and integration remain unclear. Here, we report that low-intensity ultrasound significantly increases neural progenitor cell proliferation and neuronal maturation in cortical organoids. Histological assays and single-cell gene expression analyses reveal that low-intensity ultrasound improves the neural development in cortical organoids. Following organoid grafts transplantation into the injured somatosensory cortices of adult mice, longitudinal electrophysiological recordings and histological assays reveal that ultrasound-treated organoid grafts undergo advanced maturation. They also exhibit enhanced pain-related gamma-band activity and more disseminated projections into the host brain than the untreated groups. Finally, low-intensity ultrasound ameliorates neuropathological deficits in a microcephaly brain organoid model. Hence, low-intensity ultrasound stimulation advances the development and integration of brain organoids, providing a strategy for treating neurodevelopmental disorders and repairing cortical damage.

2.
Technol Health Care ; 32(3): 1609-1618, 2024.
Article in English | MEDLINE | ID: mdl-38393931

ABSTRACT

BACKGROUND: Breast cancer has the second highest mortality rate of all cancers and occurs mainly in women. OBJECTIVE: To investigate the relationship between magnetic resonance imaging (MRI) radiomics features and histological grade of invasive ductal carcinoma (IDC) of the breast and to evaluate its diagnostic efficacy. METHODS: The two conventional MRI quantitative indicators, i.e. the apparent diffusion coefficient (ADC) and the initial enhancement rate, were collected from 112 patients with breast cancer. The breast cancer lesions were manually segmented in dynamic contrast-enhanced MRI (DCE-MRI) and ADC images, the differences in radiomics features between Grades I, II and III IDCs were compared and the diagnostic efficacy was evaluated. RESULTS: The ADC values (0.77 ± 0.22 vs 0.91 ± 0.22 vs 0.92 ± 0.20, F= 4.204, p< 0.01), as well as the B_sum_variance (188.51 ± 67.803 vs 265.37 ± 77.86 vs 263.74 ± 82.58, F= 6.040, p< 0.01), L_energy (0.03 ± 0.02 vs 0.13 ± 0.11 vs 0.12 ± 0.14, F= 7.118, p< 0.01) and L_sum_average (0.78 ± 0.32 vs 16.34 ± 4.23 vs 015.45 ± 3.74, F= 21.860, p< 0.001) values of patients with Grade III IDC were significantly lower than those of patients with Grades I and II IDC. The B_uniform (0.15 ± 0.12 vs 0.11 ± 0.04 vs 0.12 ± 0.03, F= 3.797, p< 0.01) and L_SRE (0.85 ± 0.07 vs 0.78 ± 0.03 vs 0.79 ± 0.32, F= 3.024, p< 0.01) values of patients with Grade III IDC were significantly higher than those of patients with Grades I and II IDC. All differences were statistically significant (p< 0.05). The ADC radiomics signature model had a higher area-under-the-curve value in identifying different grades of IDC than the ADC value model and the DCE radiomics signature model (0.869 vs 0.711 vs 0.682). The accuracy (0.812 vs 0.647 vs 0.710), specificity (0.731 vs 0.435 vs 0.342), positive predictive value (0.815 vs 0.663 vs 0.669) and negative predictive value (0.753 vs 0.570 vs 0.718) of the ADC radiomics signature model were all significantly better than the ADC value model and the DCE radiomics signature model. CONCLUSION: ADC values and breast MRI radiomics signatures are significant in identifying the histological grades of IDC, with the ADC radiomics signatures having greater value.


Subject(s)
Breast Neoplasms , Carcinoma, Ductal, Breast , Magnetic Resonance Imaging , Humans , Female , Breast Neoplasms/pathology , Breast Neoplasms/diagnostic imaging , Middle Aged , Carcinoma, Ductal, Breast/diagnostic imaging , Carcinoma, Ductal, Breast/pathology , Magnetic Resonance Imaging/methods , Adult , Aged , Neoplasm Grading , Retrospective Studies , Contrast Media , Radiomics
3.
J Environ Manage ; 352: 119946, 2024 Feb 14.
Article in English | MEDLINE | ID: mdl-38237337

ABSTRACT

To investigate the particle sources before, during, and after the 2022 Beijing Winter Olympic and Paralympic (WOP) in Beijing, ambient particles were passively collected from January to March 2022. The physicochemical properties including morphology, size, shape parameters, and elemental compositions were analyzed by the IntelliSEM EPAS (an advanced computer-controlled scanning electron microscopy [CCSEM] system). Using the user-defined classification rules, 37,174 individual particles were automatically classified into 27 major groups and further attributed to seven major sources based on the source-associated characteristics, including mineral dust, secondary aerosol, combustion/industry, carbonaceous particles, salt-related particles, biological particles, and fiber particles. Our results showed that mineral dust (66.5%), combustion/industry (12.6%), and secondary aerosol (6.3%) were the three major sources in a wide size range of 0.2-42.8 µm. During the Winter Olympic Games period, low emission of anthropogenic particles and favorable meteorological conditions contributed to significantly improved air quality. During the Winter Paralympic Games period, more particles sourced from the dust storm, secondary formed particles, and the adverse meteorological conditions resulted in relatively worse air quality. The secondary aerosol all decreased during the competition period, while increased during the non-competition period. Sulfate-related particles had explosive growth and further aggravate the pollution degree during the non-competition period, especially under adverse meteorological conditions. These results provide microscopic evidence revealing variations of physicochemical properties and sources in response to the control measures and meteorological conditions.


Subject(s)
Air Pollutants , Air Pollution , Beijing , Air Pollutants/analysis , Particulate Matter/analysis , Particle Size , Environmental Monitoring , Air Pollution/analysis , Dust/analysis , Seasons , Aerosols/analysis , Minerals
4.
Sci Adv ; 9(37): eadj3090, 2023 09 15.
Article in English | MEDLINE | ID: mdl-37703373

ABSTRACT

Since the initial report in 1975, the Shono oxidation has become a powerful tool to functionalize the α position of amines, including proline derivatives, by electrochemical oxidation. However, the application of electrochemical Shono oxidations is restricted to the preparation of simple building blocks and homogeneous Shono-type oxidation of proline derivatives remains challenging. The late-stage functionalization at proline residues embedded within peptides is highly important as substitutions about the proline ring are known to affect biological and pharmacological activities. Here, we show that homogenous copper-catalyzed oxidation conditions complement the Shono oxidation and this general protocol can be applied to a series of formal C-C coupling reactions with a variety of nucleophiles using a one-pot procedure. This protocol shows good tolerance toward 19 proteinogenic amino acids and was used to functionalize several representative bioactive peptides, including captopril, enalapril, Smac, and endomorphin-2. Last, peptide cyclization can also be achieved by using an appropriately positioned side-chain hydroxyl moiety.


Subject(s)
Copper , Proline , Peptides , Amino Acids , Amines , Catalysis
5.
RSC Adv ; 13(5): 3204-3209, 2023 Jan 18.
Article in English | MEDLINE | ID: mdl-36756397

ABSTRACT

Structure modification of drugs is a reliable way to optimize lead compounds, among which the most striking and direct method is late-stage functionalization (LSF). Here, we employed the Cu-catalyzed C-H LSF to modify 5-nitrofuran drugs. A series of modifications have been carried out including hydroxylation, methylation, azidination, cyanation, arylation, etc. Antibacterial activities of all compounds in vitro were measured. The results showed that compound 1 and compound 18 were the most active among all compounds. Meanwhile, the cell cytotoxicity assays of potent compounds 1, 3, 4, 5 & 18 and the parent drug FZD were conducted.

6.
Trop Med Infect Dis ; 8(1)2023 Jan 05.
Article in English | MEDLINE | ID: mdl-36668949

ABSTRACT

Schistosomiasis is still one of the most significant neglected tropical diseases worldwide, and China is endemic for Schistosoma japonicum. With its great achievement in schistosomiasis control, the government of China has set the goal to eliminate the parasitic disease at the country level by 2030. However, one major challenge is the remaining huge areas of habitats for the intermediate host Oncomelania hupensis. This is further exacerbated by an increasing number of new emerging snail habitats reported each year. Therefore, population genetics on snails in such areas will be useful in evaluation of snail control effect and/or dispersal. We then sampled snails from new emerging habitats in Taicang of Jiangsu, China, a currently S. japonicum non-endemic area from 2014 to 2017, and performed population genetic analyses based on nine microsatellites. Results showed that all snail populations had low genetic diversity, and most genetic variations originated from within snail populations. The estimated effective population size for the 2015 population was infinitive. All snails could be separated into two clusters, and further DIYABC analysis revealed that both the 2016 and the 2017 populations may derive from the 2015, indicating that the 2017 population must have been missed in the field survey performed in 2016. These findings may have implications in development of more practical guidelines for snail monitoring and control.

7.
Heliyon ; 8(12): e12074, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36561667

ABSTRACT

Safe, economical and high-quality storage of huge amount of grain for a longer duration under COVID-19 is a challenge and underground storage is a good alternative due to stable temperature, less cooling consumption and better pest control effect. However, the underground silo has very high requirement of waterproof and the performance of underground silo under combined compression and water pressure was rarely studied. In this study, a new composite structure, polypropylene - concrete wall (PPCW) for underground silo was proposed. Total three PPCWs with different size were manufactured to test the waterproofing features under joint effect of compression and hydropower of water. The strains, lateral displacement and cracking conditions of PPCWs were investigated. According to the experimental results, the PP board and concrete presented very good performance of interaction working under compression. The maximum water pressure of the specimens with stud spacing of 250mm increased by about 15.7% compared with that of the specimens with stud spacing of 350mm. The welding and strength of PP board has the greatest influence on the ultimate performance of PPCW. Based on the empirical coefficient method of concrete flat-slab and tested results, a new modified method was proposed to predict the bending moment at mid-span of PPCW by using an adjustment coefficient, R m . Considering this experimental case only, the adopting a R m = 0.64 could control the relative errors between test and analysis under 15.6%.

8.
Stem Cell Res Ther ; 13(1): 525, 2022 12 19.
Article in English | MEDLINE | ID: mdl-36536463

ABSTRACT

BACKGROUND: The effects of traumatic brain injury (TBI) can include physical disability and even death. The development of effective therapies to promote neurological recovery is still a challenging problem. 3D-printed biomaterials are considered to have a promising future in TBI repair. The injury-preconditioned secretome derived from human umbilical cord blood mesenchymal stem cells showed better stability in neurological recovery after TBI. Therefore, it is reasonable to assume that a biological scaffold loaded with an injury-preconditioned secretome could facilitate neural network reconstruction after TBI. METHODS: In this study, we fabricated injury-preconditioned secretome/collagen/heparan sulfate scaffolds by 3D printing. The scaffold structure and porosity were examined by scanning electron microscopy and HE staining. The cytocompatibility of the scaffolds was characterized by MTT analysis, HE staining and electron microscopy. The modified Neurological Severity Score (mNSS), Morris water maze (MWM), and motor evoked potential (MEP) were used to examine the recovery of cognitive and locomotor function after TBI in rats. HE staining, silver staining, Nissl staining, immunofluorescence, and transmission electron microscopy were used to detect the reconstruction of neural structures and pathophysiological processes. The biocompatibility of the scaffolds in vivo was characterized by tolerance exposure and liver/kidney function assays. RESULTS: The excellent mechanical and porosity characteristics of the composite scaffold allowed it to efficiently regulate the secretome release rate. MTT and cell adhesion assays demonstrated that the scaffold loaded with the injury-preconditioned secretome (3D-CH-IB-ST) had better cytocompatibility than that loaded with the normal secretome (3D-CH-ST). In the rat TBI model, cognitive and locomotor function including mNSS, MWM, and MEP clearly improved when the scaffold was transplanted into the damage site. There is a significant improvement in nerve tissue at the site of lesion. More abundant endogenous neurons with nerve fibers, synaptic structures, and myelin sheaths were observed in the 3D-CH-IB-ST group. Furthermore, the apoptotic response and neuroinflammation were significantly reduced and functional vessels were observed at the injury site. Good exposure tolerance in vivo demonstrated favorable biocompatibility of the scaffold. CONCLUSIONS: Our results demonstrated that injury-preconditioned secretome/collagen/heparan sulfate scaffolds fabricated by 3D printing promoted neurological recovery after TBI by reconstructing neural networks, suggesting that the implantation of the scaffolds could be a novel way to alleviate brain damage following TBI.


Subject(s)
Brain Injuries, Traumatic , Brain Injuries , Rats , Humans , Animals , Secretome , Brain Injuries, Traumatic/therapy , Brain Injuries/therapy , Collagen/chemistry , Printing, Three-Dimensional , Tissue Scaffolds/chemistry
9.
Int J Parasitol Drugs Drug Resist ; 20: 129-134, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36403362

ABSTRACT

Schistosomiasis is a major neglected tropical disease mainly caused by Schistosoma haematobium, S. japonicum and S. mansoni, and results in the greatest disease burden. Mass drug administration (MDA) with praziquantel (PZQ), a single drug only available for the disease, has played a vital role in schistosomiasis control. Therefore, any possibility of selection of the parasites for PZQ resistance or low sensitivity may hamper the 2030's target of global disease elimination. We had experimentally demonstrated the long-term survival and reproductive potential of single-sex (of either sex) S. japonicum infections in definitive hosts mice. What has not yet been adequately addressed is whether the long live single-sex schistosomes remain sensitive to PZQ, and what reproduction potential for those schistosomes surviving treatment may have. We therefore performed experimental mice studies to explore the treatment effectiveness of PZQ (at total doses of 200 or 400 mg/kg, corresponding to the sub-standard or standard treatment doses in humans) for single-sex S. japonicum aged three months old. The results showed that no treatment efficiency was observed on female schistosomes, whereas on male schistosomes only at PZQ 400 mg/kg a significant higher efficiency in reducing worm burdens was observed. Moreover, either schistosome males or females surviving PZQ treatment remained their reproduction potential as normal. The results indicate that long (i.e., three months) live single-sex S. japonicum can easily survive the current treatment strategy, and moreover, any schistosomes, if with PZQ resistance or low sensitivity, could be easily transmitted in nature. Therefore, in order to realize the target for the national and the global schistosomiasis elimination, there is undoubtedly a great need for refining PZQ administration and dosage, looking for alternative therapies, and/or developing vaccines against schistosome.


Subject(s)
Schistosoma japonicum , Schistosomiasis mansoni , Humans , Male , Female , Mice , Animals , Infant , Praziquantel/therapeutic use , Schistosomiasis mansoni/drug therapy , Schistosoma haematobium , Treatment Outcome , Schistosoma mansoni
10.
Stem Cell Res Ther ; 13(1): 378, 2022 07 28.
Article in English | MEDLINE | ID: mdl-35902882

ABSTRACT

BACKGROUND: Stroke is the leading cause of disability worldwide, resulting in severe damage to the central nervous system and disrupting neurological functions. There is no effective therapy for promoting neurological recovery. Growing evidence suggests that the composition of exosomes from different microenvironments may benefit stroke. Therefore, it is reasonable to assume that exosomes secreted in response to infarction microenvironment could have further therapeutic effects. METHODS: In our study, cerebral infarct tissue extracts were used to pretreat umbilical cord mesenchymal stem cells (UCMSC). Infarct-preconditioned exosomes were injected into rats via tail vein after middle cerebral artery occlusion (MCAO). The effect of infarct-preconditioned exosomes on the neurological recovery of rats was examined using Tunel assay, 2,3,5-triphenyltetrazolium chloride (TTC) assay, magnetic resonance imaging (MRI) analyses, modified Neurological Severity Score (mNSS), Morris water maze (MWM), and vascular remodeling analysis. Mi-RNA sequencing and functional enrichment analysis were used to validate the signal pathway involved in the effect of infarct-preconditioned exosomes. Human umbilical vein endothelial cells (HUVECs) were co-cultured with the isolated exosomes. Cell Counting Kit-8 (CCK-8) assay, scratch healing, and Western blot analysis were used to detect the biological behavior of HUVECs. RESULTS: The results showed that compared with normal exosomes, infarct-preconditioned exosomes further promoted vascular remodeling and recovery of neurological function after stroke. The function of upregulated miRNAs and their target genes which is beneficial to vascular smooth muscle cells verified the importance of vascular remodeling in improving stroke. Better resistance to oxygen-glucose deprivation/reoxygenation (OGD/R), reduced apoptosis, and enhanced migration were observed in infarct-preconditioned exosomes-treated umbilical vein endothelial cells. CONCLUSIONS: Our results demonstrated that infarct-preconditioned exosomes promoted neurological recovery after stroke by enhancing vascular endothelial remodeling, suggested that infarct-preconditioned exosomes could be a novel way to alleviate brain damage following a stroke.


Subject(s)
Exosomes , Mesenchymal Stem Cells , Stroke , Animals , Endothelial Cells , Exosomes/metabolism , Humans , Infarction, Middle Cerebral Artery , Mesenchymal Stem Cells/metabolism , Rats , Stroke/metabolism , Stroke/therapy , Umbilical Cord , Vascular Remodeling
11.
Angew Chem Int Ed Engl ; 61(31): e202205537, 2022 08 01.
Article in English | MEDLINE | ID: mdl-35610478

ABSTRACT

Regiodivergent alkene functionalization that produces either regioisomer starting from the same raw materials is desirable. Herein, we report a nickel-catalyzed switchable site-selective alkene hydroalkylation. The selection of reaction temperatures leads to protocols that provide regiodivergent hydroalkylated products starting from a single alkene substrate. This protocol allows the convenient synthesis of α- and ß-branched protected amines, both of which are important to the fields of pharmaceutical chemistry and biochemistry. In addition, enantioenriched ß-branched alkylamines can be accessed in a catalytic asymmetric variant. Preliminary mechanistic studies indicate that the formation of a more stable nickelacycle provides the driving force of migration. The thermodynamic and kinetic properties of different reduction elimination intermediates are responsible for the switchable site-selectivity.


Subject(s)
Alkenes , Nickel , Alkenes/chemistry , Amines/chemistry , Catalysis , Nickel/chemistry , Temperature
12.
Ecotoxicol Environ Saf ; 236: 113469, 2022 May 01.
Article in English | MEDLINE | ID: mdl-35367881

ABSTRACT

Long-term manganese exposure causes a neurodegenerative disorder referred to as manganese poisoning, but the mechanism remains unclear and no specific treatment is available. Oxidative stress is widely recognised as one of the main causes of manganese-induced neurotoxicity. In recent years, the role of histone acetylation in neurodegenerative diseases has been widely concerned. curcumin is a natural polyphenol compound extracted from the rhizome of turmeric and exhibits both antioxidant and neuroprotective properties. Therefore, we aimed to investigate whether and how curcumin protects against manganese-induced neurotoxicity from the perspective of histone acetylation, based on the reversibility of histone acetylation modification. In this study, rats were treated with or without curcumin and subjected to long-term manganese exposure. Results that treatment of manganese decreased the protein expression of H3K18 acetylation and H3K27 acetylation at the promoters of oxidative stress-related genes and inhibited the expression of these genes. Nevertheless, curcumin increased the H3K27 acetylation level at the manganese superoxide dismutase (SOD2) gene promoter and promoted the expression of SOD2 gene. Oxidative damage in the rat striatum as well as learning and memory dysfunction were ameliorated after curcumin treatment. Taken together, our results suggest that the regulation of oxidative stress by histone acetylation may be a key mechanism of manganese-induced neurotoxicity. In addition, curcumin ameliorates Mn-induced neurotoxicity may be due to alleviation of oxidative damage mediated by increased activation of H3K27 acetylation at the SOD2 gene promoter.


Subject(s)
Curcumin , Manganese Poisoning , Acetylation , Animals , Curcumin/pharmacology , Gene Expression , Histones/metabolism , Manganese/metabolism , Manganese/toxicity , Oxidative Stress , Rats
13.
Acta Pharmacol Sin ; 43(4): 1024-1032, 2022 Apr.
Article in English | MEDLINE | ID: mdl-34321613

ABSTRACT

Androgen receptor (AR) serves as a main therapeutic target for prostate cancer (PCa). However, resistance to anti-androgen therapy (SAT) inevitably occurs. Indomethacin is a nonsteroidal anti-inflammatory drug that exhibits activity against prostate cancer. Recently, we designed and synthesized a series of new indomethacin derivatives (CZ compounds) via Pd (II)-catalyzed synthesis of substituted N-benzoylindole. In this study, we evaluated the antitumor effect of these novel indomethacin derivatives in castration-resistant prostate cancer (CRPC). Upon employing CCK-8 cell viability assays and colony formation assays, we found that these derivatives had high efficacy against CRPC tumor growth in vitro. Among these derivatives, CZ-212-3 exhibited the most potent efficacy against CRPC cell survival and on apoptosis induction. Mechanistically, CZ-212-3 significantly suppressed the expression of AR target gene networks by degrading AR and its variants. Consistently, CZ-212-3 significantly inhibited tumor growth in CRPC cell line-based xenograft and PDX models in vivo. Taken together, the data show that the indomethacin derivative CZ-212-3 significantly inhibited CRPC tumor growth by degrading AR and its variants and could be a promising agent for CRPC therapy.


Subject(s)
Prostatic Neoplasms, Castration-Resistant , Cell Line, Tumor , Cell Proliferation , Heterografts , Humans , Indomethacin/pharmacology , Indomethacin/therapeutic use , Male , Prostatic Neoplasms, Castration-Resistant/drug therapy , Prostatic Neoplasms, Castration-Resistant/metabolism , Prostatic Neoplasms, Castration-Resistant/pathology , Receptors, Androgen/metabolism , Xenograft Model Antitumor Assays
14.
Nat Commun ; 12(1): 4342, 2021 07 15.
Article in English | MEDLINE | ID: mdl-34267229

ABSTRACT

Nitrogen heterocycle represents a ubiquitous skeleton in natural products and drugs. Late-stage C(sp3)-H bond functionalization of N-heterocycles with broad substrate scope remains a challenge and of particular significance to modern chemical synthesis and pharmaceutical chemistry. Here, we demonstrate copper-catalysed late-stage C(sp3)-H functionalizaion of N-heterocycles using commercially available catalysts under mild reaction conditions. We have investigated 8 types of N-heterocycles which are usually found as medicinally important skeletons. The scope and utility of this approach are demonstrated by late-stage C(sp3)-H modification of these heterocycles including a number of pharmaceuticals with a broad range of nucleophiles, e.g. methylation, arylation, azidination, mono-deuteration and glycoconjugation etc. Preliminary mechanistic studies reveal that the reaction undergoes a C-H fluorination process which is followed by a nucleophilic substitution.

16.
Nat Commun ; 12(1): 1313, 2021 02 26.
Article in English | MEDLINE | ID: mdl-33637730

ABSTRACT

To increase the reliability and success rate of drug discovery, efforts have been made to increase the C(sp3) fraction and avoid flat molecules. sp3-Rich enantiopure amines are most frequently encountered as chiral auxiliaries, synthetic intermediates for pharmaceutical agents and bioactive natural products. Streamlined construction of chiral aliphatic amines has long been regarded as a paramount challenge. Mainstream approaches, including hydrogenation of enamines and imines, C-H amination, and alkylation of imines, were applied for the synthesis of chiral amines with circumscribed skeleton structures; typically, the chiral carbon centre was adjacent to an auxiliary aryl or ester group. Herein, we report a mild and general nickel-catalysed asymmetric reductive hydroalkylation to effectively convert enamides and enecarbamates into drug-like α-branched chiral amines and derivatives. This reaction involves the regio- and stereoselective hydrometallation of an enamide or enecarbamate to generate a catalytic amount of enantioenriched alkylnickel intermediate, followed by C-C bond formation via alkyl electrophiles.

17.
Entropy (Basel) ; 22(6)2020 Jun 16.
Article in English | MEDLINE | ID: mdl-33286435

ABSTRACT

It is well known that Markowitz's mean-variance model is the pioneer portfolio selection model. The mean-variance model assumes that the probability density distribution of returns is normal. However, empirical observations on financial markets show that the tails of the distribution decay slower than the log-normal distribution. The distribution shows a power law at tail. The variance of a portfolio may also be a random variable. In recent years, the maximum entropy method has been widely used to investigate the distribution of return of portfolios. However, the mean and variance constraints were still used to obtain Lagrangian multipliers. In this paper, we use Conditional Value at Risk constraints instead of the variance constraint to maximize the entropy of portfolios. Value at Risk is a financial metric that estimates the risk of an investment. Value at Risk measures the level of financial risk within a portfolio. The metric is most commonly used by investment bank to determine the extent and occurrence ratio of potential losses in portfolios. Value at Risk is a single number that indicates the extent of risk in a given portfolio. This makes the risk management relatively simple. The Value at Risk is widely used in investment bank and commercial bank. It has already become an accepted standard in buying and selling assets. We show that the maximum entropy distribution with Conditional Value at Risk constraints is a power law. Algebraic relations between the Lagrangian multipliers and Value at Risk constraints are presented explicitly. The Lagrangian multipliers can be fixed exactly by the Conditional Value at Risk constraints.

18.
J Appl Toxicol ; 40(12): 1661-1672, 2020 12.
Article in English | MEDLINE | ID: mdl-32608101

ABSTRACT

Long-term arsenic exposure is a worldwide public health problem that causes serious harm to human health. The liver is the main target organ of arsenic toxicity; arsenic induces disruption of the DNA damage repair pathway, but its mechanisms remain unclear. In recent years, studies have found that epigenetic mechanisms play an important role in arsenic-induced lesions. In this study, we conducted experiments in vitro using normal human liver cells (L-02) to explore the mechanism by which the histone demethylase JHDM2A regulates H3K9 dimethylation (me2) in response to arsenic-induced DNA damage. Our results indicated that arsenic exposure upregulated the expression of JHDM2A, downregulated global H3K9me2 modification levels, increased the H3K9me2 levels at the promoters of base excision repair (BER) genes (N-methylpurine-DNA glycosylase [MPG], XRCC1 and poly(ADP-ribose)polymerase 1) and inhibited their expression levels, causing DNA damage in cells. In addition, we studied the effects of overexpression and inhibition of JHDM2A and found that JHDM2A can participate in the molecular mechanism of arsenic-induced DNA damage via the BER pathway, which may not be involved in the BER process because H3K9me2 levels at the promoter region of the BER genes were unchanged following JHDM2A interference. These results suggest a potential mechanism by which JHDM2A can regulate the MPG and XRCC1 genes in the process of responding to DNA damage induced by arsenic exposure and can participate in the process of DNA damage repair, which provides a scientific basis for understanding the epigenetic mechanisms and treatments for endemic arsenic poisoning.


Subject(s)
Arsenic Poisoning/etiology , Arsenites/toxicity , Chemical and Drug Induced Liver Injury/etiology , DNA Damage , DNA Repair , Histones/metabolism , Jumonji Domain-Containing Histone Demethylases/metabolism , Liver/drug effects , Sodium Compounds/toxicity , Arsenic Poisoning/enzymology , Arsenic Poisoning/genetics , Arsenic Poisoning/pathology , Cell Line , Chemical and Drug Induced Liver Injury/enzymology , Chemical and Drug Induced Liver Injury/genetics , Chemical and Drug Induced Liver Injury/pathology , DNA Glycosylases/genetics , DNA Glycosylases/metabolism , Humans , Jumonji Domain-Containing Histone Demethylases/genetics , Liver/enzymology , Liver/pathology , Methylation , Poly (ADP-Ribose) Polymerase-1/genetics , Poly (ADP-Ribose) Polymerase-1/metabolism , Promoter Regions, Genetic , X-ray Repair Cross Complementing Protein 1/genetics , X-ray Repair Cross Complementing Protein 1/metabolism
19.
J Comput Assist Tomogr ; 44(3): 328-333, 2020.
Article in English | MEDLINE | ID: mdl-32345806

ABSTRACT

OBJECTIVE: To establish the normal parameters of fetal lung development at different gestational ages and to study their correlation with gestational age, thereby providing clinicians with a noninvasive method for assessing fetal lung maturity. METHODS: Two hundred eight cases with pregnancy of 22 to 39 weeks plus 6 days were divided into 18 groups according to gestational age. Ultrasound Doppler was used to measure the relevant parameters of fetal pulmonary development, including right pulmonary left and right diameter, right pulmonary upper and lower diameter, right pulmonary anterior and posterior diameter, right pulmonary area, thoracic area, inner diameter of fetal main pulmonary artery, and Doppler velocity curve parameters of main pulmonary artery: systolic acceleration time (AT), ejection time (ET), AT/ET. RESULTS: This study establishes normal parameters of lung development at different gestational weeks, draws scatter plots, correlation, and regression analysis of fetal main pulmonary artery AT, ET, AT/ET, and gestational weeks; selects the optimal equation; and analyzes the correlation among right pulmonary left and right diameter, right pulmonary upper and lower diameter, right pulmonary anterior and posterior diameter, right lung diameter, right lung area, thoracic area, and gestational weeks; and draw growth curve. The diameter of main pulmonary artery, AT, and AT/ET increased with the increase of gestational age and were positively correlated with gestational age (r = 0.948, 0.875, 0.810; P = 0.012). Ejection time had no correlation with gestational weeks. There were significant differences in the diameter of main pulmonary artery, AT, AT/ET between different gestational weeks (F = 240.67, 41.137, 23.067; P = 0.024); left and right diameter of right lung, anterior and posterior diameter of right lung, upper and lower diameter of right lung, chest area and right lung area were positively correlated with gestational weeks, and there were significant differences between different gestational weeks (F = 190.85, 105.74, 34.97, 172.33, 35.33, P = 0.018). CONCLUSIONS: Ultrasound Doppler can be used as a noninvasive detecting equipment to evaluate the growth of fetal lung, thus providing a basis for the evaluation of fetal lung maturity.


Subject(s)
Lung , Pulmonary Artery , Ultrasonography, Prenatal , Adult , Female , Humans , Lung/diagnostic imaging , Lung/embryology , Predictive Value of Tests , Pregnancy , Pregnancy Trimester, Third/physiology , Pulmonary Artery/diagnostic imaging , Pulmonary Artery/embryology , Young Adult
20.
Molecules ; 25(5)2020 Mar 09.
Article in English | MEDLINE | ID: mdl-32182955

ABSTRACT

We developed an efficient method for synthesis of substituted N-benzoylindole via Pd(II)-catalyzed C-H functionalization of substituted N-(2-allylphenyl)benzamide. The reaction showed a broad substrate scope (including N-acetyl and N-Ts substrates) and substituted indoles were obtained in good to excellent yields. The most distinctive feature of this method lies in the high selectivity for N-benzoylindole over benzoxazine, and this is the first example of Pd(II)-catalyzed synthesis of substituted N-benzoylindole. Notably, this new method was applied for the synthesis of key intermediate of indomethacin.


Subject(s)
Benzamides/chemical synthesis , Indoles/chemical synthesis , Indomethacin/chemical synthesis , Benzamides/chemistry , Catalysis , Cyclization , Indoles/chemistry , Indomethacin/chemistry , Palladium/chemistry
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