Hazard analysis and countermeasures of periodic electrical switching to medical equipment in hospital / 中国医学装备

Objective:To establish safety objectives and strategies for power distribution of medical equipment to minimize the hazard of electrical switching to medical equipment.Methods:Based on the Hazard Analysis and Risk Assessment(HARA)method,the equipment hazard factors analysis and risk assessment were conducted for electrical switching from the perspective of medical equipment safety management.The Deming Cycle(PDCA)closed-loop management process was adopted to formulate refined the medical equipment power distribution safety objectives and response strategies.Results:In 2023,a total of 6 equipment failures occurred during the two periodic electrical shutdown operations carried out in the hospital's power distribution room,which was significantly lower than the average of 20.4 failures caused by electrician shutdowns from 2018 to 2022,and zero failure in Level I load department and other high-risk areas.Conclusion:The objective and strategy of power distribution safety of medical equipment are highly targeted and implemented,which is an effective way to implement the life cycle fine management of medical equipment.

Study on HPLC Fingerprint and Multi-Index Components Contents of Atractylodis Macrocephalae Rhizoma / 中药新药与临床药理

Objective To establish a method for simultaneous determination of HPLC fingerprint and multi-target ingredients in Atractylodis Macrocephalae Rhizoma(AMR),in order to provide reference for its quality control.Methods HPLC-DAD multi-wavelength switching method was used to establish fingerprint of AMR,similarity evaluation combined with hierarchical clustering analysis(HCA),principal components analysis(PCA)and discriminant analysis of partial least squares(PLS-DA)were used to carry out chemometric study.The contents of differential component such as atractylenolide Ⅰ,Ⅱ,Ⅲ and atractylon were determined simultaneously.Results The HPLC fingerprint of 37 batches of AMR was established.Nine common peaks were marked,and 4 of them were identified as atractylon,atractylenolide Ⅰ,Ⅱ,Ⅲ.The similarity degrees were between 0.539 and 0.996,the quality of AMR from different origin and different batches varies greatly.Atractylon,atractylenolide Ⅰ,Ⅱ,Ⅲ and one unknown component(peak 9)are the important factors affecting the quality of AMR.Conclusion The combination methods of HPLC fingerprint and simultaneous determinations of multiple components are simple,stable,accurate and reliable,which can provide reference for the quality evaluation of AMR and the improvement of quality standard,as well as lay a foundation for the basic research of its pharmacodynamic substances and related compound.

Pruritus Caused by the Change in Hydromorphone Formulation Disappeared after Switching to the Fentanyl Patch: A Case Report

Systemic administration of opioids rarely causes pruritus, although its mechanism is still not clearly understood. We report an intractable pruritus induced by a change in the dosage form of opioids with the same dose by the conversion ratio, which promptly disapeared with opioid switching. A 80-year-old female experienced worsening dorsal pain and abdominal pain due to recurrent pancreatic cancer. The relief of pain was insufficient with the administration of oral hydromorphone 10 mg/day, changing to continuous intravenous hydromorphone 3 mg/day considering adjustability. The next day, her pain was reduced, but the pruritus appeared. Administering oral and topical antihistamines was ineffective. Her pruritus tended to worsen with continued administration of continuous intravenous hydromorphone at the same dose. Hence we switched to fentanyl patch 0.6 mg/day. The following day, her pruritus significantly decreased, and two days later, her pruritus almost disappeared. This case suggests that opioids switching to fentanyl patch may be effective to relieve pruritus caused by hydromorphone.

Features of dominant eye and the significance of ocular dominance switching in the treatment of ocular diseases / 中华实验眼科杂志

The dominant eye is the eye that plays a significant role in visual perception.It plays an essential role in binocular vision and fusion functions with a complex formation mechanism.According to the principle of the dominant eye examination method, ocular dominance can be classified into sighting, motor, and sensory dominance.Changes in visual acuity or visual function due to the unbalanced progression of binocular disease may lead to the switch in the dominant eye, affecting the balance of binocular vision and the therapeutic effect.Therefore, misjudging or neglecting of the dominant eye will change the long-term visual balance between the eyes, which may affect people's visual quality and quality of life.These aspects are mainly represented in the process of refractive error correction, refractive surgery, strabismus correction surgery, amblyopia training methods and cataract intraocular lens measurement.The formulation of medical plans based on the strategy of the dominant eye can remarkably improve the reconstruction good binocular vision and the quality of life of patients.However, the role of the dominant eye in binocular vision is not fully understood, and clinicians are not sufficiently aware of its importance.Therefore, this study will review the latest research progress on the mechanism of dominant eye formation, examination methods, and clinical significance of dominant eye switching.

Drug survival and change of disease activity using a second janus kinase inhibitor in patients with difficult-to-treat rheumatoid arthritis who failed to a janus kinase inhibitor and subsequent biologics

Abstract Background To assess the drug survival and change of disease activity using a second Janus kinase inhibitor (JAKi) after failure to a JAKi and subsequent biologic disease-modifying anti-rheumatic drugs (bDMARDs) in patients with difficult-to-treat rheumatoid arthritis (RA). Methods This retrospective cohort study included 32 patients with difficult-to-treat RA who failed to a JAKi and subsequently to one or more bDMARDs and then switched to a second JAKi. To assess drug survival, electronic medical records of each patient were reviewed. Data on whether the second JAKi was discontinued, and the reasons for discontinuation were collected. The change of disease activity was assessed by analyzing changes in tender joint count (TJC), swollen joint count (SJC), patient's global assessment of disease activity on a visual-analogue scale (VAS), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Disease Activity Score for 28 joints with ESR (DAS28-ESR), and DAS28-CRP from baseline to that at six months from initiation of the second JAKi. Results Overall, discontinuation of the second JAKi occurred in 20 (62.5%) patients. Primary failure, secondary failure, adverse events, and insurance coverage issues were the reasons for discontinuation in 9 (45.0%), 5 (25.0%), 2 (10.0%), and 4 (20.0%) patients, respectively. The estimated 2-year drug survival rate was 39.3%. In terms of change of disease activity, the second JAKi significantly improved TJC (p < 0.001), SJC (p < 0.001), VAS (p < 0.001), CRP (p = 0.026), DAS28-ESR (p < 0.001), and DAS28-CRP (p < 0.001) at 6-month compared with that at the baseline. Conclusions Second JAKi could be a therapeutic option in patients with difficult-to-treat RA who have failed to a JAKi and subsequent bDMARDs.

Multitasking in postanesthesia care unit following nurse interruptions, an analysis of the causes and consequences using classification tree: an observational prospective study

Abstract Background: Postanesthesia Care Unit (PACU) is an environment associated with an important workload which is susceptible to lead to task interruption (TI), leading to task-switching or concurrent multitasking. The objective of the study was to determine the predictors of the reaction of the nurses facing TI and assess those who lead to an alteration of the initial task. Methods: We conducted a prospective observational study into the PACU of a university hospital during February 2017. Among 18 nurses, a selected one was observed each day, documenting for each TI the reaction of the nurse (task switching or concurrent multitasking), and the characteristics associated with the TI. We performed classification tree analyses using C5.0 algorithm in order to select the main predictors of the type of multitasking performed and the alteration of the initial task. Results: We observed 1119 TI during 132 hours (8.5 TI/hour). The main reaction was concurrent multitasking (805 TI, 72%). The short duration of the task interruption (one minute or less) was the most important predictor leading to concurrent multitasking. Other predictors of response to TI were the identity of the task interrupter and the number of nurses present. Regarding the consequences of the task switching, long interruption (more than five minutes) was the most important predictor of the alteration of the initial task. Conclusions: By analysing the predictors of the type of multitasking in front of TI, we propose a novel approach to understanding TI, offering new perspective for prevention strategies.

Three-dimensional finite element analysis of cement flow in abutment margin-crown platform switching / 北京大学学报(医学版)

OBJECTIVE@#To analyze the cement flow in the abutment margin-crown platform switching structure by using the three-dimensional finite element analysis, in order to prove that whether the abutment margin-crown platform switching structure can reduce the inflow depth of cement in the implantation adhesive retention.@*METHODS@#By using ANSYS 19.0 software, two models were created, including the one with regular margin and crown (Model one, the traditional group), and the other one with abutment margin-crown platform switching structure (Model two, the platform switching group). Both abutments of the two models were wrapped by gingiva, and the depth of the abutment margins was 1.5 mm submucosal. Two-way fluid structure coupling calculations were produced in two models by using ANSYS 19.0 software. In the two models, the same amount of cement were put between the inner side of the crowns and the abutments. The process of cementing the crown to the abutment was simulated when the crown was 0.6 mm above the abutment. The crown was falling at a constant speed in the whole process spending 0.1 s. Then we observed the cement flow outside the crowns at the time of 0.025 s, 0.05 s, 0.075 s, 0.1 s, and measured the depth of cement over the margins at the time of 0.1 s.@*RESULTS@#At the time of 0 s, 0.025 s, 0.05 s, the cements in the two models were all above the abutment margins. At the time of 0.075 s, in Model one, the gingiva was squeezed by the cement and became deformed, and then a gap was formed between the gingiva and the abutment into which the cement started to flow. In Model two, because of the narrow neck of the crown, the cement flowed out from the gingival as it was pressed by the upward counterforce from the gingival and the abutment margin. At the time of 0.1 s, in Model one, the cement continued to flow deep inside with the gravity force and pressure, and the depth of the cement over the margin was 1 mm. In Model two, the cement continued to flow out from the gingival at the time of 0.075 s, and the depth of the cement over the margin was 0 mm.@*CONCLUSION@#When the abutment was wrapped by the gingiva, the inflow depth of cement in the implantation adhesive retention can be reduced in the abutment margin-crown platform switching structure.

Comprehensive Quality Evaluation of Croci Stigma Based on Entropy Weight TOPSIS Method / 医药导报

Objective To comprehensively evaluate the quality of Croci Stigma from different regions by using the entropy weighted TOPSIS,and to provide evidence for the quality evaluation and regions selection of Croci Stigma.Methods The contents of picrocrocin,crocin I,crocin II and crocin III were determined by HPLC wavelength switching method.The total content of four components,loss on drying,total ash,absorbance and extract were chosen as detection indexes for Croci Stigma,and the weight was calculated by entropy weight method,and the indexes were statistically analyzed by TOPSIS method.The quality of Croci Stigma was comprehensively evaluated.Results The analysis results of entropy weighted TOPSIS method showed that the mean values of relative closeness(Ci)values of Croci Stigma from Zhejiang,Tibet,Anhui,Jiangsu provinces and shanghai city were 0.654,0.396,0.426,0.326 and 0.341,respectively.Overall,the quality of Croci Stigma in Zhejiang province was the highest.Conclusion The established entropy weighted TOPSIS method is objective,comprehensive and effective,which can be used for the comprehensive quality evaluation of Croci Stigma.

Terpine-4-ol on inhibiting vascular smooth muscle cell calcification by improving mitochondrial dynamics / 药学学报

The aim of this study was to investigate the role and mechanism of terpinen-4-ol (T4O) on high glucose (HG) -induced calcification in vascular smooth muscle cell (VSMC). To investigate the role of T4O on HG-induced calcium deposition, osteogenic phenotypic transformation and mitochondrial dynamics in VSMC, Mdivi-1, a mitochondrial dynamin-related protein 1 (Drp-1) inhibitor, was used to analyze the correlation between mitochondrial dynamics and VSMC calcification and the role of T4O. Alizarin red S staining was used to observe calcium salt deposition and flow cytometry to detect intracellular Ca2+ content; Western blot and immunofluorescence were used to detect the expression of phenotypic switching-related markers α-smooth muscle actin (α-SMA), bone morphogenetic protein 2 (BMP2) and Runt related transcription factor 2 (Runx2), and mitochondrial dynamics-related markers mitofusin 1 (MFN1), mitofusin 2 (MFN2) and Drp-1. The results showed that low and high doses of T4O could inhibit HG-induced down-regulation of α-SMA, MFN1 and MFN2 expression levels, and up-regulation of BMP2, Runx2 and Drp-1 expression levels, reduce intracellular Ca2+ content and calcium salt deposition, and effectively inhibit HG-induced VSMC calcification and mitochondrial dynamics disorders. The T4O group, Mdivi-1 group and T4O+Mdivi-1 group were able to up-regulate the expression levels of HG-induced α-SMA, MFN1 and MFN2, down-regulate the protein expression levels of BMP2, Runx2 and Drp-1, and inhibit calcium salt deposition, and there was no significant difference between the above indexes in the T4O and T4O+Mdivi-1 groups. The above findings suggest that T4O can inhibit the expression level of Drp-1, regulate the disturbance of mitochondrial dynamics, and suppress HG-induced VSMC calcification.

Peri-implant bone level assessment of early loaded dental implants submitted to different prosthetic protocols: a case report / Avaliação do nível ósseo peri-implantar de implantes dentários com carregamento antecipado submetidos a protocolos protéticos diferentes: relato de caso

Aim: The present split-mouth case report aims to describe the clinical and radiographic long-term outcomes of the implant rehabilitation of two mandibular premolars in which the digital workflow was used to apply different prosthetic protocols. Case description: A female 42-year-old patient with the absence of both mandibular second premolars was submitted to guided surgery for the placement of platform-switching Grand Morse connection implants. Digital workflow was used for implant and prosthetic planning, applying early loading protocol 21 days after surgery. The implant on the right side received the final abutment at the time of surgery (without loading), whereas the implant on the left side had a healing abutment placed, which was replaced by a temporary abutment and then by a final abutment. Two months after surgery, both implants had final ceramic restorations delivered. The patient was followed clinically and radiographically for 30 months, presenting excellent hard and soft tissue outcomes, with bone level changes lower than 2mm for both implants. Conclusion: The use of digital workflow and early loading, made the present implant-supported rehabilitation predictable, safe and time-efficient, resulting in total patient satisfaction. Peri-implant bone level was observed to be stable after early loading protocol for both platform-switching connection implants inserted, despite the prosthetic protocol applied.(AU)

Objetivo: O presente relato de caso de boca dividida tem como objetivo descrever os resultados clínicos e radiográficos a longo prazo da reabilitação com implante de dois pré-molares inferiores em que o fluxo de trabalho digital foi usado para aplicar os conceitos de "one abutment-one time" em uma das reabilitações e troca de componente no outro. Descrição do caso: Paciente do sexo feminino, 42 anos, com ausência de ambos os segundos pré-molares inferiores, foi submetida à cirurgia guiada para colocação de implantes de conexão Grand Morse plataforma-switching. Foi utilizado fluxo de trabalho digital para planejamento de implante e prótese, aplicando protocolo de carga antecipada 21 dias após a cirurgia. O implante do lado direito recebeu o componente protético definitivo no momento da cirurgia (sem carga), enquanto o implante do lado esquerdo recebeu um cicatrizador, que foi substituído por um pilar provisório e depois por um componente definitivo. Dois meses após a cirurgia, ambos os implantes tiveram restaurações cerâmicas finais entregues. A paciente foi acompanhada clínica e radiograficamente por 30 meses, apresentando excelentes resultados de tecidos duros emoles, com alterações do nível ósseo inferiores a 2mm para ambos os implantes. Conclusão: O fluxo de trabalho digital e carregamento precoce, tornou a presente reabilitação implantossuportada previsível, segura e eficiente em termos de tempo, resultando em total satisfação do paciente. O nível ósseo peri-implantar foi observado como estável após o protocolo de carregamento inicial para ambos os implantes de conexão plataforma-switching inseridos, independente do protocolo protético aplicado. (AU)

Code-Switching Between Arabic and English in Selected Discourses

Code-switching is a linguistic phenomenon that has been studied on both written and spoken discourses in the recent years. This study is an attempt to analyze code-switching in selected discourses. The data were collected from Arabic Interviews on YouTube. The first interview 'Studying in the best university ever' is a broadcast by Abdullah Al-Alawy. The second interview 'Karak session' is with the broadcaster Mohammed Al-Hinai. The methodology of this study was a mixed (quantitative as well as qualitative) method. The research tries to answer three questions: 1.How many code- switching Instincts from Arabic language to English language occurred in the selected discourses? 2. Is there any translation for the code-switching? If yes, then where the translation takes its place whether before or after the code- switching? 3. How many intra-word switching occur by using Arabic grammatical morphemes within these English code-switching? The research's primary goal is to improve our understanding of the instinctive uses of code-switching from Arabic to English. In this study I found that there are 101 occurrences of code-switching within about forty minutes of Arabic discourses. The most frequent type of code-switching in these two discourses was intra-sentential code-witching. While the least used one was inter-sentential code-switching. Most of the code-switching Instincts occurred without any translation to Arabic

Predictors of efficacy of corticosteroid switching from abiraterone plus prednisone to dexamethasone in patients with metastatic castration-resistant prostate cancer / 亚洲男科学杂志(英文版)

Corticosteroid switching can reverse abiraterone resistance in some patients with metastatic castration-resistant prostate cancer (mCRPC). Here, we investigated the potential biomarkers for predicting the efficacy of corticosteroid switching during treatment with abiraterone acetate (AA). We retrospectively analyzed 101 mCRPC patients receiving corticosteroid switching from West China Hospital and Sun Yat-Sen University Cancer Center between January 2016 and December 2018. All cases received AA plus prednisone as first-line therapy during mCRPC. Primary end points were biochemical progression-free survival (bPFS) and overall survival (OS). The risk groups were defined based on multivariate analysis. A total of 42 (41.6%) and 25 (24.8%) patients achieved 30% and 50% decline in prostate-specific antigen (PSA), respectively, after corticosteroid switching. The median bPFS and median OS on AA plus dexamethasone were 4.9 (95% confidence interval [CI]: 3.7-6.0) months and 18.8 (95% CI: 16.2-30.2) months, respectively. Aldo-keto reductase family 1 member C3 (AKR1C3) expression (hazard ratio [HR]: 2.15, 95% Cl: 1.22-3.80, P = 0.008) and baseline serum alkaline phosphatase (ALP; HR: 4.95, 95% Cl: 2.40-10.19, P < 0.001) were independent predictors of efficacy before corticosteroid switching in the multivariate analysis of bPFS. Only baseline serum ALP >160 IU l-1 (HR: 3.41, 95% Cl: 1.57-7.38, P = 0.002) together with PSA level at switch ≥50 ng ml-1 (HR: 2.59, 95% Cl: 1.22-5.47, P = 0.013) independently predicted poorer OS. Based on the predictive factors in multivariate analysis, we developed two risk stratification tools to select candidates for corticosteroid switching. Detection of serum ALP level, PSA level, and tissue AKR1C3 expression in mCRPC patients could help make clinical decisions for corticosteroid switching.

Efficacy and safety of switching from brand-name to domestic generic levetiracetam in children with epilepsy / 中国当代儿科杂志

OBJECTIVES@#To study the efficacy and safety of domestic generic levetiracetam in replacement of brand-name levetiracetam in the treatment of children with epilepsy.@*METHODS@#A retrospective analysis was performed on the medical data of 154 children with epilepsy who received domestic generic levetiracetam in the inpatient or outpatient service of Guangdong Provincial People's Hospital from May 2019 to December 2020. Domestic generic levetiracetam and brand-name levetiracetam were compared in terms of efficacy and safety.@*RESULTS@#For these 154 children, the epilepsy control rate was 77.3% (119/154) at baseline. At 6 months after switching to domestic generic levetiracetam, the epilepsy control rate reached 83.8% (129/154), which showed a significant increase (P<0.05). There was no significant change in the frequency of seizures from baseline to 6 months after switching (P>0.05). The incidence of refractory epilepsy in children with no response after switching treatment was significantly higher than that in children with response (P<0.05). Before switching, only 1 child (0.6%) experienced somnolence, while after switching, 3 children (1.9%) experienced mild adverse drug reactions, including dizziness, somnolence, irritability, and bad temper.@*CONCLUSIONS@#Switching from brand-name to generic levetiracetam is safe and effective and holds promise for clinical application, but more prospective randomized controlled trials are required in future.

Overview of miRNA involved in PASMCs phenotypic switching in pulmonary hypertension / 中国药理学通报

Pulmonary hypertension ( PH) is occult, with no distinctive clinical manifestations and poor prognosis.Pulmonary vascular remodelling is an important pathological feature in which pulmonary artery smooth muscle cell ( PASMCs) pheno- typic switching plays a crucial role.MicroRNA (miRNA) is a class of evolutionary highly conserved single-stranded small non-coding RNA.Recently, an increasing number of scholars have found that miRNA can play an important role in the occurrence and development of PH by regulating the phenotypic switching of PASMCs, which is expected to be a potential target for the prevention and treatment of PH.It has been found that miR NA such as miR-221 , miR-24, miR-15b, miR-96, miR-23a.miR-9, miR-214, miR-20a can promote the phenotypic switching of PASMCs, while miRNA such as miR-21, miR-132, miR-182, miR-449, miR-206 .miR-124, miR-30c, miR-140.miR-17-92 cluster can inhibit it.This article aims to review the research progress on miRNA that mediates PASMCs phenotypic switching in PH from both growth factor-related miRNA and hy- poxia-related miRNA.

A Retrospective Survey of 28 Cases with Opioid Switching by Adding Methadone to the Preceding Opioid

The guide to proper use of methadone in Japan describes the SAG method (a method of stopping all leading opioids and starting methadone). Based on strict evaluation, our palliative care department introduces methadone by adding to the preceding opioid, and then tapering or discontinuation the preceding opioid. This time, we considered the clinical significance of 28 patients who received this method. In 20 of 28 cases (71.4%), methadone reached the maximum dose, and methadone titration could be safely performed without exacerbation of pain or serious adverse events. However, in order for this method to be performed safely, it is necessary to pay attention to the pharmacological properties of methadone, which has a long half-life, and to make a detailed evaluation and drug adjustment of the analgesic effect and adverse events after the introduction of methadone.

Simultaneous Determination of 5 Components in the Classical Formula Huaihua San by HPLC Wavelength Switching Method / 中国药房

OBJECTIVE：To develop a method for simultaneous determination of 5 components in classical formula Huaihua san，including rutin ，naringin，neohesperidin，quercetin and pulegone. METHODS ：HPLC wavelength switching method was adopted. The determination was performed on Cosmosil C 18 column with mobile phase consisted of acetonitrile- 0.05％ phosphoric acid solution （gradient elution ）at the flow rate of 1.0 mL/min. The detection wavelengths were set at 257 nm for rutin ，283 nm for naringin and neohesperidin ，254 nm for quercetin ，252 nm for pulegone ，respectively. The column temperature was set at 30 ℃， and sample size was 10 μL. RESULTS：The linear range was 21.7-2 170 μg/mL for rutin，46-4 600 μg/mL for naringin，22.3- 2 230 μg/mL for neohesperidin，0.96-96 μg/mL for quercetin，2.7-270 μg/mL for pulegone（all r＞0.999），respectively. RSDs of precision，stability（24 h）and reproducibility tests were all lower than 2％（n＝6）. Average recoveries were 100.70％，99.31％， 101.10％，100.03％ and 99.63％（all RSD ＜2％，n＝9）. Among 3 batches of Huaihua san samples ，the contents of above 5 components were 20.055-22.615，25.557-27.806，11.428-13.250，0.350-0.478，2.372-4.011 mg/g，respectively. CONCLUSIONS ： Established method is simple ，accurate and reproducible ，and could be used for the simultaneous determination of 5 components in Huaihua san.

Research on polymer impurities in cefazolin sodium raw materials and products / 药学学报

Research on polymer impurities has always been important in the quality control of cephalosporins. Research on polymers in cephalosporins that lack active amino groups on the C-7 side chain has not been reported. Therefore, our study used cefazolin sodium, which is widely used in the clinic, as an example. The polymer in cefazolin sodium and its product "cefazolin sodium pentahydrate for injection" was analyzed by column switching liquid chromatography-high resolution mass spectrometry. Two polymer impurity peaks were detected and the possible structures of these polymers were suggested. Through two-dimensional liquid chromatography, the chromatographic peaks following Sephadex gel chromatography and high-performance gel chromatography were compared to those obtained by reverse high-performance liquid chromatography (HPLC) for cefazolin sodium as reported in the Chinese Pharmacopoeia. The HPLC method proves more suitable for polymer detection than Sephadex gel chromatography and high-performance gel chromatography. The method of polymer detection for cefazolin sodium was established using the method of related substances HPLC as described in the Chinese Pharmacopoeia.

Simultaneous Determination of 12 Components in the Classical Formula Sanhua Tang by HPLC-multi-wavelength Switching Technology / 中国药房

OBJECTIVE：To establish a method for simultaneous determination of 12 components including naringin ， hesperidin，neohesperidin，aloe emodin ，rhein，notopterol，emodin，honokiol，isoimperatorin，magnolol，chrysophanol and physcion in classical formula Sanhua tang. METHODS ： HPLC-multi-wavelength switching technology was adopted. The determination was performed on COSMOSIL C 18 with mobile phase consisted of acetonitrile- 0.1％ phosphoric acid （gradient elution）at the flow rate of 1.0 mL/min. The detection wavelength was 280 nm（naringin，hesperidin，neohesperidin），254 nm （aloe emodin ，rhein，chrysophanol，emodin methyl ether ），310 nm（notopterol，emodin，honokiol，isoimperatorin，magnolol）. The column temperature was set at 30 ℃，and the sample size was 10 μL. RESULTS：A total of 12 components were well separated without negative interference. The linear range of naringin ，hesperidin，neohesperidin，aloe emodin ，rhein，notopterol， emodin，honokiol，isoimperatorin，magnolol，chrysophanol and physcion were 55.4-5 540，3.8-380，45.6-4 560，1.2-120， 2.1-210，2.2-220，2-200，2.4-240，0.8-80，1.2-120，1.7-170，1.1-110 μg/mL（R 2≥0.999 6），respectively. The detection limits were 0.064，0.024，0.053，0.018，0.020，0.041，0.050，0.091，0.030，0.180，0.028 and 0.083 μg/mL，respectively. The limits of quantitation were 0.213，0.075，0.174，0.060，0.063，0.138， 0.166，0.323，0.130，0.600，0.094 and 0.275 μ g/mL，respec- 9721004） tively. RSDs of precision ，stability （24 h） and repeatability 2633531778@qq.com tests were all lower than 2％（n＝6）. Average recoveries were 99.54％，99.69％，100.01％，99.93％，100.36％，99.65％， 100.03％，100.47％，99.97％，100.68％，99.90％，100.17％ （all RSDs were lower than 2％，n＝6），respectively. CONCLUSIONS ：Established HPLC-multi- wavelength switching technology is simple ，specific and stable ，which could be used for the simultaneous determination of 12 components in Sanhua tang as naringin，hesperidin，neohesperidin.

Quorum sensing-induced phenotypic switching as a regulatory nutritional stress response in a competitive two-species biofilm: An individual-based cellular automata model

Competition for nutrients in a polymicrobial biofilm may lead to susceptible species being subjected to nutritionalstress. The influence of bacterial growth rates and interspecies interactions on their susceptibility and response tonutritional stress is not well understood. Pseudomonas aeruginosa and Staphylococcus aureus are two prevalentcausative pathogens that coexist in biofilm-associated infections. Despite being the slower-growing species, P.aeruginosa dominates in a two-species biofilm by inducing phenotypic switching of S. aureusto a metabolicallychallenged small colony variant (SCV) via the release of 2-heptyl-4-hydroxyquinoline N-oxide (HQNO). Wehypothesize that P. aeruginosa experiences nutritional stress in competition with S. aureus, and that the release ofHQNO is an adaptive response to nutritional stress. We present an individual-based two-species biofilm model inwhich interactions between entities induce emergent properties. As the biofilm matured, the difference in growthrates of the two species caused a non-uniform distribution of nutrients leading to nutritional stress for P. aeruginosa and a concurrent increase in the proportion of S. aureus subpopulation. The latter resulted in increasedrelease of autoinducer, and subsequently the upregulation of P. aeruginosa cells via quorum sensing. UpregulatedP. aeruginosa cells released HQNO at enhanced rates, thereby inducing phenotypic switching of S. aureus toSCVs which consume nutrient at a reduced rate. This shifted the nutrient distribution back in favor of P.aeruginosa, thereby relieving nutritional stress. Increase in nutritional stress potentiated the transformation of S.aureus into SCVs. HQNO production decreased once nutritional stress was relieved, indicating that phenotypicswitching acts as a regulatory stress-adaptive response.

RP-HPLC-DAD determination of free amino acids in cocoa samples during fermentation and roasting / Determinación de aminoácidos libres en muestras de cacao durante la fermentación y el tostado por cromatografía líquida con detección DAD / Determinação de aminoácidos livres em amostras de cacau durante a fermentação e torrefação por cromatografia líquida com detecção DAD

Abstract Amino acids (AA) composition in cocoa beans can predict the synthesis of compounds which affect cocoa flavor. Thus, their determination is of great interest for the community implied in the commercialization and production of cocoa. In consequence, in this work, the analysis of AA produced during cocoa beans fermentation and roasting was carried out. A high-performance liquid chromatographic method with DAD detection at 254 nm was optimized and validated for their selective determination in six varieties of cocoa beans with different genotypes, all of them grown in Venezuela. AA were extracted by defatted milled cocoa powder ultrasonication using purified water at 70 °C. Then, they were derivatized with phenyl isothiocyanate, and their derivatives were separated, using a reversed-phase column with gradient elution, achieving a satisfactory resolution among the peaks (greater than 1.0) in less than 29 min. 110 cocoa samples were analyzed. Results showed a significant content of free AA, ranging from 3.87 to 5.97 g/kg in absence of fermentation with a predominance of acidic AA. Moreover, there is a progressive increase in the AA content while fermentation process occurs, with a predominance of hydrophobic AA such as alanine, valine, isoleucine, leucine, phenylalanine, and tyrosine. On the other hand, all cocoa types showed a partial degradation of free AA during the roasting step, especially the hydrophobic ones.

Resumen La determinación de aminoácidos (AA) en granos de cacao es de gran interés ya que estos son considerados como unos de los precursores de su sabor y aroma. Por esta razón, el presente trabajo tuvo como objetivo optimizar y validar un método por cromatografía líquida con detección DAD a 254 nm para la determinación selectiva de AA durante la fermentación y tostado en seis variedades de granos de cacao con diferentes genotipos, todos estos cultivados en Venezuela. Los AA se extrajeron del polvo de cacao molido y desgrasado con agua pura a 70 ºC, utilizando la técnica de ultrasonido. Luego, se derivatizaron con fenilotiocianato para separar sus derivados con buena resolución en menos de 29 min en una columna de fase reversa, utilizando gradiente de elución. Se analizaron 110 muestras de cacao. Los resultados mostraron un contenido significativo de AA libres, entre 3,87 y 5,97 g/kg, en ausencia de fermentación con predominio de AA ácidos, y un aumento progresivo en el contenido de AA, mientras ocurre el proceso de fermentación, con un predominio de AA hidrófobos como alanina, valina, isoleucina, leucina, fenilalanina y tirosina. Además, todos los tipos de cacao mostraron una degradación parcial de AA libres durante la etapa de tostado, especialmente los AA hidrófobos.

Resumo A determinação dos aminoácidos (AA) nos grãos de cacau é importante, pois são considerados um dos precursores de seu sabor e aroma. Neste trabalho, um método foi otimizado e validado por cromatografia líquida com detecção DAD a 254 nm para a determinação seletiva de AA durante a fermentação e torrefação em seis variedades de grãos de cacau com diferentes genótipos, todos cultivados na Venezuela. Os AAs foram extraídos do pó de cacau moído e desengordurados com água pura a 70 ºC usando a técnica de ultrassom. Em seguida, foram derivatizados com feniltiocianato, e os derivados foram separados com boa resolução em menos de 29 minutos em uma coluna de fase invertida usando eluição em gradiente. Foram analisadas 110 amostras de cacau. Os resultados mostraram um conteúdo significativo de AA livre entre 3,87 e 5,97 g/kg na ausência de fermentação com predominância de AA ácidos e um aumento progressivo no conteúdo de AA enquanto o processo de fermentação ocorre com predominância de AA hidrófobos como alanina, valina, isoleucina, leucina, fenilalanina e tirosina. Além disso, todos os tipos de cacau apresentaram uma degradação parcial do AA livre durante a fase de torrefação, principalmente o AA hidrofóbico.