Compared with conventional radiotherapy fields, small field has unique dosimetry characteristics such as high dose gradient, charged particle imbalance, and dose effect caused by source occlusion. These characteristics increase the difficulty of dose measurement and thus the uncertainty of clinical dose measurement, far exceeding the requirement of < 5% measurement error in ICRU 24 report. In recent years, with the development of new radiotherapy technologies, the minimum radiotherapy field can reach the millimeter level, and the single irradiation dose of hypofractionated radiotherapy can exceed 6 Gy. The larger dose gradient at the edge of radiotherapy field requires higher accuracy of dose measurement, and accurate small field dosimetry technologies have gradually become a research hotspot in the field of precision radiotherapy. In order to ensure the high accuracy of measurement, this paper reviews the research on small field dosimetry worldwide, and summarizes the key points of small field dosimetry. In this paper, the characteristics of small field dosimetry are introduced, and the current small field dosimetry technologies and optimization methods are summarized, including the optimization of detector selection and detector sensitive volume. The field output correction factor technologies are analyzed. In view of the difficulty in small field dosimetry, this paper provides suggestions on dosimetry based on clinical needs and the characteristics of medical linear accelerators. Our suggestions provide a scientific reference for small field dosimetry in clinical practice in radiotherapy institutions, and facilitate the development of radiotherapy dose verification.

Rare diseases have a significant and profound impact on society, the economy, and the healthcare system. The path to developing drugs for rare diseases is particularly arduous. Due to the small number of patients and limited market demand, pharmaceutical companies don′t have enough incentives and resources to invest in drug research and development. Additionally, the long development cycles, high costs, and high risks have led to a number of potential therapeutic drug failures at the early stages of development. This article summarizes a series of encouraging policies adopted by the National Medical Products Administration for rare diseases, which is an important public health issue, as well as the achievements in the review and approval of rare disease drugs in recent years. These policies have accelerated the approval process. Meanwhile, the policies ensure the safety and effectiveness of drugs and offer more treatment options and hopes to patients with rare diseases. With the continuous effort at optimizing the policy environment and the advancement of research and development technologies, China′s drug regulatory authorities will continue to focus on the clinical needs of rare diseases, to implement " patient-centered " approach to drug development, inject new vitality into the research and development of drugs of rare diseases, and offer more precise and effective treatment choices for patients with rare diseases.

Objective To explore the risk factors related to afterload mismatch(AM)after transcatheter mitral valve repair(MitraClip).Methods This was a retrospective cohort study.48 patients hospitalized in the Department of Cardiovascular Medicine,the First Affiliated Hospital of Sun Yat-sen University from December 2021 to December 2023,who underwent MitraClip due to severe mitral regurgitation(MR)were included.Preoperative clinical data,laboratory tests,and preoperative and postoperative color Doppler echocardiographic examination results of surgical patients were collected.AM was defined as the left ventricular ejection fraction(LVEF)decreased by 15％or more after surgery compared with the one before(dLVEF≤-15％).Patients were divided into AM group and non-AM group according to whether afterload mismatch occurred.Univariate and multivariate logistic regression were used to analyze the risk factors of postoperative AM.Results Among 48 patients who underwent MitraClip,14 of them(29.2％)developed afterload-mismatched.For those without AM,their overall LVEF was improved after the operation;for patients in both AM group and non-AM group,their overall left ventricular end-diastolic diameter(LVEDd),left ventricular end-diastolic diameter volume index(LVEDVi)was reduced compared with the preoperative ones.Univariate regression analysis showed that C-reactive protein levels(OR 1.98,95％CI 1.02-3.83),platelets(OR 2.22,95％CI 1.08-4.53),systemic immune inflammation index(OR 1.96,95％CI 1.03-3.71)were associated with an increased risk of AM in patients undergoing MitraClip(all P＜0.05),while those with larger right atrial diameter(OR 0.35,95％CI 0.13-0.93)or moderate to severe tricuspid regurgitation(OR 0.19,95％CI 0.05-0.81)were less likely to develop into AM(both P＜0.05),which is still satisfied after adjustment.Conclusions For patients who underwent MitraClip,C-reactive protein levels,platelets and systemic immune inflammation index(SII)are associated with an increased risk of afterload mismatched,while those with larger right atrial diameter or moderate to severe tricuspid regurgitation were less likely to develop into AM.

Norepinephrine (NE) modulates synaptic transmission and long-term plasticity through distinct subtype adrenergic receptor (AR)-mediated-intracellular signaling cascades. However, the role of NE modulates glutamatergic long-term potentiation (LTP) in the hypothalamic paraventricular nucleus (PVN) magnocellular neuroendocrine cells (MNCs) is unclear. We here investigate the effect of NE on high frequency stimulation (HFS)-induced glutamatergic LTP in rat hypothalamic PVN MNCs in vitro, by whole-cell patch-clamp recording, biocytin staining and pharmacological methods. Delivery of HFS induced glutamatergic LTP with a decrease in N2/N1 ratio in the PVN MNCs, which was enhanced by application of NE (100 nM).HFS-induced LTP was abolished by the blockade of N-methyl-D-aspartate receptors (NMDAR) with D-APV, but it was rescued by the application of NE. NE failed to rescue HFS-induced LTP of MNCs in the presence of a selective β1-AR antagonist, CGP 20712. However, application of β1-AR agonist, dobutamine HCl rescued HFS-induced LTP of MNCs in the absence of NMDAR activity. In the absence of NMDAR activity, NE failed to rescue HFS-induced MNC LTP when protein kinase A (PKA) was inhibited by extracellular applying KT5720 or intracellular administration of PKI. These results indicate that NE activates β1-AR and triggers HFS to induce a novel glutamatergic LTP of hypothalamic PVN NMCs via the postsynaptic PKA signaling pathway in vitro in rats.

Norepinephrine (NE) modulates synaptic transmission and long-term plasticity through distinct subtype adrenergic receptor (AR)-mediated-intracellular signaling cascades. However, the role of NE modulates glutamatergic long-term potentiation (LTP) in the hypothalamic paraventricular nucleus (PVN) magnocellular neuroendocrine cells (MNCs) is unclear. We here investigate the effect of NE on high frequency stimulation (HFS)-induced glutamatergic LTP in rat hypothalamic PVN MNCs in vitro, by whole-cell patch-clamp recording, biocytin staining and pharmacological methods. Delivery of HFS induced glutamatergic LTP with a decrease in N2/N1 ratio in the PVN MNCs, which was enhanced by application of NE (100 nM).HFS-induced LTP was abolished by the blockade of N-methyl-D-aspartate receptors (NMDAR) with D-APV, but it was rescued by the application of NE. NE failed to rescue HFS-induced LTP of MNCs in the presence of a selective β1-AR antagonist, CGP 20712. However, application of β1-AR agonist, dobutamine HCl rescued HFS-induced LTP of MNCs in the absence of NMDAR activity. In the absence of NMDAR activity, NE failed to rescue HFS-induced MNC LTP when protein kinase A (PKA) was inhibited by extracellular applying KT5720 or intracellular administration of PKI. These results indicate that NE activates β1-AR and triggers HFS to induce a novel glutamatergic LTP of hypothalamic PVN NMCs via the postsynaptic PKA signaling pathway in vitro in rats.

Norepinephrine (NE) modulates synaptic transmission and long-term plasticity through distinct subtype adrenergic receptor (AR)-mediated-intracellular signaling cascades. However, the role of NE modulates glutamatergic long-term potentiation (LTP) in the hypothalamic paraventricular nucleus (PVN) magnocellular neuroendocrine cells (MNCs) is unclear. We here investigate the effect of NE on high frequency stimulation (HFS)-induced glutamatergic LTP in rat hypothalamic PVN MNCs in vitro, by whole-cell patch-clamp recording, biocytin staining and pharmacological methods. Delivery of HFS induced glutamatergic LTP with a decrease in N2/N1 ratio in the PVN MNCs, which was enhanced by application of NE (100 nM).HFS-induced LTP was abolished by the blockade of N-methyl-D-aspartate receptors (NMDAR) with D-APV, but it was rescued by the application of NE. NE failed to rescue HFS-induced LTP of MNCs in the presence of a selective β1-AR antagonist, CGP 20712. However, application of β1-AR agonist, dobutamine HCl rescued HFS-induced LTP of MNCs in the absence of NMDAR activity. In the absence of NMDAR activity, NE failed to rescue HFS-induced MNC LTP when protein kinase A (PKA) was inhibited by extracellular applying KT5720 or intracellular administration of PKI. These results indicate that NE activates β1-AR and triggers HFS to induce a novel glutamatergic LTP of hypothalamic PVN NMCs via the postsynaptic PKA signaling pathway in vitro in rats.

Norepinephrine (NE) modulates synaptic transmission and long-term plasticity through distinct subtype adrenergic receptor (AR)-mediated-intracellular signaling cascades. However, the role of NE modulates glutamatergic long-term potentiation (LTP) in the hypothalamic paraventricular nucleus (PVN) magnocellular neuroendocrine cells (MNCs) is unclear. We here investigate the effect of NE on high frequency stimulation (HFS)-induced glutamatergic LTP in rat hypothalamic PVN MNCs in vitro, by whole-cell patch-clamp recording, biocytin staining and pharmacological methods. Delivery of HFS induced glutamatergic LTP with a decrease in N2/N1 ratio in the PVN MNCs, which was enhanced by application of NE (100 nM).HFS-induced LTP was abolished by the blockade of N-methyl-D-aspartate receptors (NMDAR) with D-APV, but it was rescued by the application of NE. NE failed to rescue HFS-induced LTP of MNCs in the presence of a selective β1-AR antagonist, CGP 20712. However, application of β1-AR agonist, dobutamine HCl rescued HFS-induced LTP of MNCs in the absence of NMDAR activity. In the absence of NMDAR activity, NE failed to rescue HFS-induced MNC LTP when protein kinase A (PKA) was inhibited by extracellular applying KT5720 or intracellular administration of PKI. These results indicate that NE activates β1-AR and triggers HFS to induce a novel glutamatergic LTP of hypothalamic PVN NMCs via the postsynaptic PKA signaling pathway in vitro in rats.

Norepinephrine (NE) modulates synaptic transmission and long-term plasticity through distinct subtype adrenergic receptor (AR)-mediated-intracellular signaling cascades. However, the role of NE modulates glutamatergic long-term potentiation (LTP) in the hypothalamic paraventricular nucleus (PVN) magnocellular neuroendocrine cells (MNCs) is unclear. We here investigate the effect of NE on high frequency stimulation (HFS)-induced glutamatergic LTP in rat hypothalamic PVN MNCs in vitro, by whole-cell patch-clamp recording, biocytin staining and pharmacological methods. Delivery of HFS induced glutamatergic LTP with a decrease in N2/N1 ratio in the PVN MNCs, which was enhanced by application of NE (100 nM).HFS-induced LTP was abolished by the blockade of N-methyl-D-aspartate receptors (NMDAR) with D-APV, but it was rescued by the application of NE. NE failed to rescue HFS-induced LTP of MNCs in the presence of a selective β1-AR antagonist, CGP 20712. However, application of β1-AR agonist, dobutamine HCl rescued HFS-induced LTP of MNCs in the absence of NMDAR activity. In the absence of NMDAR activity, NE failed to rescue HFS-induced MNC LTP when protein kinase A (PKA) was inhibited by extracellular applying KT5720 or intracellular administration of PKI. These results indicate that NE activates β1-AR and triggers HFS to induce a novel glutamatergic LTP of hypothalamic PVN NMCs via the postsynaptic PKA signaling pathway in vitro in rats.

Abstract：Objective To predict the structure and function of sterol O⁃acyltransferase 1（SOAT1）related to hepatocellular carcinoma（HCC）by using bioinformatics tools，in order to understand its mechanism as the marker and therapeutic target of S⁃Ⅲ subtype. Methods The structure，function and protein interaction of SOAT1 were predicted and analyzed by using databases or softwares such as NCBI，STRING，Protscale，SignalP，TMHMM，PSORT，SOPMA，SWISS ⁃ MODEL， NetNGlyc，NetOGlyc，Netphos and ProtParam. Results The protein encoded by SOAT1 was a hydrophobic protein with good stability，which was a nonclassical pathway protein with 8 transmembrane regions，mainly distributed among the cell membrane. SOAT1 was expressed in many tissues，while most of them in the adrenal gland，which showed multiple phosphorylation sites and was mainly involved in the synthesis and catabolism of cholesterol. Conclusion Bioinformatics analysis of structure and function of SOAT1 showed that SOAT1 lipid synthesis and catabolism pathways played an important role，and lipid expression was closely related to the development of cancer，indicating that the treatment of HCC may be achieved by regulating the expression of SOAT1 gene.

AIM: To study the correlation between meibomian gland dysfunction(MGD)patients and their sleep quality.METHODS: Retrospective case-control study. A total of 150 MGD patients treated in our hospital from January 2021 to October 2022 were selected and divided into sleep disorder group(75 cases, PSQI>10 points)and control group(75 cases, PSQI≤10 points)according to the Pittsburgh sleep quality index(PSQI). Both groups were scored using the ocular surface disease index(OSDI), underwent meibomian gland-related examinations(eyelid margin morphology, meibomian gland secretion ability, meibomian gland secretion quality score), corneal fluorescein staining(FL)score, Schirmer Ⅰ test(SⅠt), tear film break-up time(BUT)was measured, and sleep indicators(sleep quality, sleep latency, subjective sleep quality, sleep time)were evaluated.RESULTS: There were significant differences in OSDI score, FL score, SⅠt, BUT, eyelid margin morphology score, meibomian gland secretion ability score, and meibomian gland secretion quality score between the two groups(P<0.05). In the sleep disorder group, PSQI score, sleep latency score, subjective sleep quality score, and sleep time score were significantly positively correlated with OSDI score, FL score, meibomian gland secretion ability score, and meibomian gland secretion quality score(P<0.05); PSQI score, subjective sleep quality score, and sleep time score were significantly positively correlated with eyelid margin morphology score(P<0.05); PSQI score, sleep latency score, and subjective sleep quality score were significantly negatively correlated with BUT and SⅠt(P<0.05); sleep time score was significantly negatively correlated with BUT(P<0.05); sleep latency score was not significantly correlated with eyelid margin morphology score(P>0.05); sleep time score was not significantly correlated with SⅠt(P>0.05).CONCLUSION:The ocular surface condition of MGD patients is correlated with multiple sleep quality indicators, and a decline in sleep quality may increase the risk of MGD.