Objective To establish an HPLC method to determine the concentration of inositol nicotinate（IN） in rat skin, and study the pharmacokinetic characteristics of IN after transdermal administration of heparin sodium inositol nicotinate cream in rats. Methods HPLC method was used to establish a simple and rapid analytical method for the determination of IN concentration in the skin of rats at different time points after administration. The established method was used to study the pharmacokinetics of IN after transdermal administration of heparin sodium inositol nicotinate cream in rats, and the pharmacokinetic parameters were fitted with DAS software. Results The linearity of the analytical method was good in the concentration range of 0.25-20 μg/ml, the quantitative limit was 0.25 μg/ml, and the average recovery rate was 96.18%. The pharmacokinetic parameters of IN after transdermal administration of heparin sodium inositol nicotinate cream in rats were as follows: t_1/2 was （4.555±2.054） h, T_max was （6±0）h, C_max was （16.929±2.153）mg/L, AUC_0−t was （150.665±16.568） mg·h /L ,AUC_0−∞ was （161.074±23.917） mg·h /L, MRT_（0−t） was （9.044±0.618）h, MRT_{（0−∞）} was （10.444±1.91） h, CLz/F was （0.19±0.03） L/（h·kg）, and Vz/F was （1.19±0.437） L/（h·kg）. Conclusion IN could quickly penetrate the skin and accumulate in the skin for a long time, which was beneficial to the pharmacological action of drugs on the lesion site for a long time. The method is simple, rapid, specific and reproducible, which could be successfully applied to the pharmacokinetic study of IN after transdermal administration in rats.

As a serine protease,thrombin can convert soluble fibrinogen into insoluble fibrin and plays a pivotal role in the coagulation cascade.Therefore,the accurate quantitative assay of thrombin levels is of great value in the evaluation of coagulation function,clinical screening and prognostic monitoring of coagulation-related diseases,and screening of drugs for targeted therapy.Existing methods for thrombin detection can be divided into two categories,e.g.,the assay of concentration levels using nucleic acid aptamers as the affinity elements and the assay of activity levels based on the hydrolytic cleavage of substrate peptides.In recent years,electrochemical biosensors have attracted much attention in thrombin detection due to high sensitivity,high selectivity,simple instrument,fast response,and good portability.In this review,the latest research progress in methods for electrochemical detection of thrombin was summarized,focusing on the detection principles and the applied signal amplification strategies of related electrochemical biosensors.In addition,the challenges with respect to the practical use of electrochemical thrombin biosensors and the prospects were discussed.

Objective To develop an ultra-high performance liquid chromatography-mass spectrometry method(UPLC-MS/MS)for the determination of nirmatrelvir concentration in mouse plasma.Methods The ACQUITY UPLC system was used in tandem with an API 4000 triple quadrupole mass spectrometer.The analytical column was Waters BEH C18(2.1 mm×5.0 mm,1.7 μm)column,and the mobile phases consisted of water(containing 0.1％formic acid)and methanol(containing 0.1％formic acid)under gradient elution at the flow rate of 0.4 mL·min-1.The column temperature was set at 40 ℃,and the injection volume was 5 μL.Electrospray ionization was used as ion source,and positive multiple reaction monitoring mode was adopted to quantitatively analyze the ionization pairs m/z 500.3→110.3(nirmatrelvir)and m/z 237.3→193.3(carbamazepine).Carbamazepine was employed as an internal standard.Results The linear range of nirmatrelvir was from 10 ng·mL-1 to 2 560 ng·mL-1.For the quality control nirmatrelvir samples,the accuracies of intra-and inter-batch were less than±15％,and the precisions of intra-and inter-batch were lower than 15％.Nirmatrelvir in plasma was stable at room temperature for 24 h and remained stable after three freeze-thaw cycles.The extracted nirmatrelvir solution could be stored at 4℃ for 3 d without any visible change.Conclusion The method was characterized by good specificity,high sensitivity,and appropriate linear range.The methodological validation was in accordance with the 2020 edition of the Chinese Pharmacopoeia and could be applied to the quantitative detection of nirmatrelvir in plasma.

Endoplasmic reticulum stress(ERS)is associated with the pathophysiology of various lung diseases.Multiple experiments have confirmed that inhibiting ERS can alleviate inflammatory responses,improve lung function,and possess certain anti-infective effects.ERS inhibitors can positively impact the treatment of respiratory system diseases by targeting the unfolded protein response(UPR)in the ERS pathway and regulating the balance of calcium ions within the endoplasmic reticulum.Most current research on ERS inhibitors is still in the preclinical stage.This article thoroughly reviews the relevant reviews and various experimental research results on ERS in respiratory diseases,systematically examining the potential roles of the main branches of UPR,including inositol requiring enzyme 1 alpha(IRE 1α),protein kinase-like endoplasmic reticulum kinase(PERK),and activated transcription factor 6(ATF6),as well as other ERS inhibitors in respiratory diseases.The aim is to promote clinical trial exploration of ERS inhibitors,with the hope of providing effective drug selection strategies for the treatment and symptom relief of respiratory diseases.

Objective To develop an ultra-high performance liquid chromatography-mass spectrometry method(UPLC-MS/MS)for the determination of nirmatrelvir concentration in mouse plasma.Methods The ACQUITY UPLC system was used in tandem with an API 4000 triple quadrupole mass spectrometer.The analytical column was Waters BEH C18(2.1 mm×5.0 mm,1.7 μm)column,and the mobile phases consisted of water(containing 0.1％formic acid)and methanol(containing 0.1％formic acid)under gradient elution at the flow rate of 0.4 mL·min-1.The column temperature was set at 40 ℃,and the injection volume was 5 μL.Electrospray ionization was used as ion source,and positive multiple reaction monitoring mode was adopted to quantitatively analyze the ionization pairs m/z 500.3→110.3(nirmatrelvir)and m/z 237.3→193.3(carbamazepine).Carbamazepine was employed as an internal standard.Results The linear range of nirmatrelvir was from 10 ng·mL-1 to 2 560 ng·mL-1.For the quality control nirmatrelvir samples,the accuracies of intra-and inter-batch were less than±15％,and the precisions of intra-and inter-batch were lower than 15％.Nirmatrelvir in plasma was stable at room temperature for 24 h and remained stable after three freeze-thaw cycles.The extracted nirmatrelvir solution could be stored at 4℃ for 3 d without any visible change.Conclusion The method was characterized by good specificity,high sensitivity,and appropriate linear range.The methodological validation was in accordance with the 2020 edition of the Chinese Pharmacopoeia and could be applied to the quantitative detection of nirmatrelvir in plasma.

Endoplasmic reticulum stress(ERS)is associated with the pathophysiology of various lung diseases.Multiple experiments have confirmed that inhibiting ERS can alleviate inflammatory responses,improve lung function,and possess certain anti-infective effects.ERS inhibitors can positively impact the treatment of respiratory system diseases by targeting the unfolded protein response(UPR)in the ERS pathway and regulating the balance of calcium ions within the endoplasmic reticulum.Most current research on ERS inhibitors is still in the preclinical stage.This article thoroughly reviews the relevant reviews and various experimental research results on ERS in respiratory diseases,systematically examining the potential roles of the main branches of UPR,including inositol requiring enzyme 1 alpha(IRE 1α),protein kinase-like endoplasmic reticulum kinase(PERK),and activated transcription factor 6(ATF6),as well as other ERS inhibitors in respiratory diseases.The aim is to promote clinical trial exploration of ERS inhibitors,with the hope of providing effective drug selection strategies for the treatment and symptom relief of respiratory diseases.

As a long-standing research focus in electroanalytic chemistry,electrochemical biosensors have attracted immense interest in detection of biological targets such as small molecules,proteins,enzymes,nucleic acids,exosomes,circulating tumor cells (CTCs),bacteria,and viruses. etc. The highly sensitive and selective electrochemical detection of biological targets relies on the use of the specific biorecognition elements (BREs) and efficient signal amplification strategies. In this review,the typically used BREs and amplification strategies in electrochemical biosensing were summarized. On the basis of the interactions between BREs and targets,the enzyme/substrate-based and receptor/ligand-based electrochemical biosensors were first introduced,focusing on the BREs used in the electrochemical detection of nucleic acid targets and non-nucleic acid targets. Then,the representative use of various isothermal nucleic acid amplification technologies,catalytic reactions,functionalized nanocarriers,and polymer materials in amplified electrochemical detection of biological targets were introduced. The challenges with respect to the practical use of electrochemical biosensors and the prospect of electrochemical biosensing were discussed.

Objective To explore the imaging features of primary cardiac tumors detected by echocardiography,CT and MR in children,and to analyze the value of each examination and the clinical examination strategies.Methods The clinical,pathological and imaging data of the children with primary cardiac tumors confirmed by surgery and pathology from Jun 2008 to Feb 2022 in Children's Hospital,Fudan University were analyzed retrospectively.Tumor size,location,motion,signal characteristics on different sequences,and pericardial involvement were evaluated on MR images.Results A total of 23 children(16 males and 7 females)were included.The age of onset ranged from 1 month to 13 years old,average on(54.45±58.57)months.While the onset age of rhabdomyomas was only(7.23±6.30)months.The clinical manifestations mainly included 6 cases of cardiac murmur,3 cases of cardiac insufficiency,3 cases of epilepsy,2 cases of cerebral infarction,and 1 case of arrhythmia.Pathological results showed that there were 22 cases of benign tumors(9 cases of fibromas,8 cases of myxomas,4 cases of rhabdomyomas and 1 case of lipoma)and 1 case of malignant tumor(rhabdomyosarcoma).Echocardiography has a high diagnostic accuracy for myxoma.CT showed a case of malignant rhabdomyosarcoma with invasion of the pericardium and compression of the pulmonary artery and bronchus.MR showed that the fibroma had significantly late gadolinium enhancement.The signal of rhabdomyoma was equal on T1WI,and slightly increased on T2WI,perfusion and late gadolinium enhancement sequences.Myxoma had high signal on T2WI and late gadolinium enhancement.It had obvious motions in Cine sequence.The signal of lipoma on each sequence was consistent with that of fat tissue,and there was no high signal of perfusion and late gadolinium enhancement.Conclusion All types of primary cardiac tumors in children have imaging characteristics.MR has great advantages in diagnosing cardiac tumors.The clinical team needs to select the appropriate examination method according to the actual medical situation.

【Objective】 Corin, a transmembrane serine protease that can cleave atrial natriuretic peptide precursor (pro-ANP) into atrial natriuretic peptide with smaller bioactive molecules, participates in the pathophysiological process of hypertension and cardiac hypertrophy. The purpose of this study was to explore the relationship of Corin gene variation with blood pressure responses to sodium and potassium dietary interventions. 【Methods】 In 2004, we recruited 514 participants from 124 families in 7 villages of Baoji, Shaanxi Province, China. All the subjects received a 3-day normal diet, a 7-day low-salt diet, a 7-day high-salt diet, and finally a 7-day high-salt and potassium supplementation. Fifteen single nucleotide polymorphisms (SNPs) of Corin gene were selected for final analysis. 【Results】 SNPs rs12509275 were significantly associated with diastolic blood pressure (DBP) response to low-salt diet, while rs3749584 was associated with pulse pressure (PP) response to low-salt diet.SNP rs3749584 and rs10517195 were significantly associated with PP response to high-salt diet. In addition,rs17654278 were significantly associated with systolic blood pressure (SBP) response to high-salt and potassium supplementation, rs2271037 was significantly correlated with DBP responses to high-salt and potassium supplementation, and rs4695253, rs12509275, rs2351783, rs36090894 were significantly associated with PP response to high-salt and potassium supplementation. 【Conclusion】 Corin gene polymorphisms were associated with blood pressure response to sodium and potassium, suggesting that Corin gene may be involved in pathophysiological process of salt sensitivity and potassium sensitivity.

Melasma， as a kind of melanosis， often occurs over the face of young and middle-aged women， which seriously affects the physical and mental health of patients. At present， it is believed that the occurrence of melasma is related to various factors such as ultraviolet radiation and changes in sex hormone levels in the body. However， the exact pathogenesis of melasma is still unclear and its clinical efficacy is not ideal. Therefore， it is of great clinical significance and social value to carry out basic researches on melasma diseases. Among them， the animal model of melasma acts as an important tool for studying melasma， and it is particularly important to clarify the pathophysiological mechanism of the occurrence and development of melasma. The common modeling methods include ultraviolet modeling， progesterone modeling and ultraviolet combined with progesterone modeling. However， there are still some problems in the practical application of animal models of melasma due to many influencing factors in the preparation of such animal models， and there is still a lack of a more complete and recognized model preparation scheme to this day， which reduces the success rate of model preparation and limits its application and popularization to some extent. In view of the key problems in the establishment and application of animal models of melasma， we comprehensively summarized the research status of the models from such aspects as experimental animals， modeling methods and model evaluation， and discussed the effects of different modeling methods and animal species， animal age and other factors on animal model of melasma by referring to and sorting out the recent literatures at home and abroad in recent years. This is to provide references for the preparation of more scientific， reasonable， economic and convenient animal models of melasma， lay a foundation for in-depth researches on the pathogenesis， prevention and treatment of melasma， and also provide reference for other animal model research.