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Chu CY, Cho YT, Jiang JH, Chang CC, Liao SC, Tang CH. Patients with chronic urticaria have a higher risk of psychiatric disorders: a population-based study. Br J Dermatol 2019; 182:335-341. [PMID: 31220338 DOI: 10.1111/bjd.18240] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2019] [Indexed: 12/15/2022]
Abstract
BACKGROUND The prevalence of psychiatric comorbidities in patients with chronic urticaria (CU) in a national population is largely unknown. OBJECTIVES To investigate the prevalence of psychiatric disorders and psychiatric medication use in patients with CU in Taiwan. METHODS Data were sourced from Taiwan's National Health Insurance Research Database for 2011. Patients who had a primary/secondary International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code of 708·1, 708·8 or 708·9 during 2011 with at least two outpatient visits and an antihistamine prescription were identified as CU cases. Patients with CU were classified into three disease severity groups according to their medication types. Psychiatric disorders were identified by patients having three outpatient visits with a primary or secondary diagnosis of a given psychiatric disease. Psychiatric medication use was defined by having at least four outpatient visits with prescriptions for anxiolytics, antidepressants or sleeping pills in 2010 or 2011. RESULTS Of the 167 132 patients with CU, 82·5% had mild CU, 17·0% had moderate CU and 0·4% had severe CU. Patients with CU had a higher prevalence of psychiatric disorders and psychiatric medication prescription than control groups. The relative risk (RR) of psychiatric disorders was 1·43 for patients with mild, 1·50 for patients with moderate and 2·32 for patients with severe CU vs. the controls (P < 0·001). For psychiatric medication prescription, the RRs were 1·95, 2·70 and 2·09, respectively, vs. controls (P < 0·001). CONCLUSIONS Patients with CU had a higher prevalence and risk of psychiatric disorders and psychiatric medication prescription than control groups. What's already known about this topic? Previous studies have shown a high prevalence of psychiatric comorbidities in patients with chronic urticaria (CU), with rates ranging from 35% to 60%. Anxiety, depression and somatoform disorders have been reported as the most prevalent mental disorders in patients with CU. What does this study add? Patients with CU had a higher prevalence of psychiatric disorders and psychiatric medication use than control groups in the general population. The relative risk (RR) of psychiatric disorders was 1·43 for those with mild CU, 1·50 for those with moderate CU and 2·32 for those with severe CU vs. controls. The RR for psychiatric medication use was 1·95 for those with mild CU, 2·70 for those with moderate CU and 2·09 for those with severe CU vs. controls. Mental health evaluations and management are important elements in CU management.
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Chang T, Ho HL, Hsu SJ, Chang CC, Tsai MH, Huo TI, Huang HC, Lee FY, Hou MC, Lee SD. Glucobrassicin Metabolites Ameliorate the Development of Portal Hypertension and Cirrhosis in Bile Duct-Ligated Rats. Int J Mol Sci 2019; 20:ijms20174161. [PMID: 31454890 PMCID: PMC6747388 DOI: 10.3390/ijms20174161] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 08/11/2019] [Accepted: 08/24/2019] [Indexed: 01/24/2023] Open
Abstract
Patients suffering from liver cirrhosis are often complicated with the formation of portosystemic collateral vessels, which is associated with the progression of a splanchnic hyperdynamic circulatory state. Alleviating pathological angiogenesis has thus been proposed to be a feasible treatment strategy. Indole-3-carbinol (C9H9NO, I3C) and 3,3'-diindolymethane (DIM), formed by the breakdown of glucosinolate glucobrassicin, are prevalent in cruciferous vegetables and have anti-angiogenesis properties. We aimed to evaluate their influences on portal hypertension, the severity of mesenteric angiogenesis, and portosystemic collaterals in cirrhosis. Sprague-Dawley rats with common bile duct ligation (CBDL)-induced liver cirrhosis or sham operation (surgical control) were randomly allocated to receive I3C (20 mg/kg/3 day), DIM (5 mg/kg/day) or vehicle for 28 days. The systemic and portal hemodynamics, severity of portosystemic shunting, mesenteric angiogenesis, and mesenteric proangiogenic factors protein expressions were evaluated. Compared to vehicle, both DIM and I3C significantly reduced portal pressure, ameliorated liver fibrosis, and down-regulated mesenteric protein expressions of vascular endothelial growth factor and phosphorylated Akt. DIM significantly down-regulated pErk, and I3C down-regulated NFκB, pIκBα protein expressions, and reduced portosystemic shunting degree. The cruciferous vegetable byproducts I3C and DIM not only exerted a portal hypotensive effect but also ameliorated abnormal angiogenesis and portosystemic collaterals in cirrhotic rats.
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Chang CC, Huang PC. Carbon allowance allocation in the shipping industry under EEDI and non-EEDI. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 678:341-350. [PMID: 31075601 DOI: 10.1016/j.scitotenv.2019.04.215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 04/12/2019] [Accepted: 04/13/2019] [Indexed: 06/09/2023]
Abstract
The CO2 emissions targets in this study are based on the Paris Agreement, which aims to cut emissions in 2050 to half of the 2005 levels, with a focus on the shipping industry. This study uses data for various kinds of vessels following the guidelines set in the Energy Efficiency Design Index (EEDI) and examines emission levels and the results of using different strategies during three different business climates. Carbon allowance allocations and cost benefit ratios (CBR) are included. The results show that the minimal free carbon allowances in 2050 for vessels in keeping with EEDI or non-EEDI scenarios should be set so that (1) under prosperous business cycles they are 29% and 14%; (2) under steady business cycles 83% and 42%; (3) under sluggish business cycles 510% and 255%, respectively. In addition, when shipping companies follow the emission cap guidelines, the CBR in 2050 for vessels in both scenarios will be (1) 37.52% and 47.45% during prosperous business cycles; (2) 43.49% and 45.65%during steady business cycles; (3) and 53.60% and 53.83% during sluggish business cycles, respectively. The results indicate that during prosperous business cycles, although the free carbon allowance for shipping companies will be greatly insufficient, their profits will still be higher than during sluggish business cycles.
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Chang CC, Lirng JF, Wang PN, Wang SJ, Chen CH, Yang LY, Huang WJ, Huang HC. A pilot study of integrating standardized patients in problem-based learning tutorial in Taiwan. J Chin Med Assoc 2019; 82:464-468. [PMID: 31008811 DOI: 10.1097/jcma.0000000000000109] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Problem-based learning (PBL) has been widely adopted in medical education; however, its application has been questioned due to the lack of interaction with a real patient. Standardized patients (SPs) might solve this problem. Herein, we tested the impact of integrating SPs in a PBL tutorial. METHODS In 2017, a total of 313 students, 66 facilitators, and 36 SPs were enrolled at National Yang-Ming University, Taiwan. The SPs presented the symptoms/signs of the cases then the students interviewed them to obtain the detail history. All students, facilitators, and SPs were invited to complete the questionnaires before and after this program. RESULTS Most SPs considered that both the second-year dental medical student and third-year medical students participated actively and were competent enough but students and facilitators considered that the fourth-year medical students might be more prepared. Overall, the students thought highly of the interactions with the SPs. Only about one-fifth felt that this design caused unnecessary pressure among the students and facilitators. They agreed that this program significantly inspired the student's learning motivation (pre- vs post-course: 4.1 ± 0.7 vs 4.3 ± 0.7, p < 0.001), increased their confidence level in interviewing patients (4.0 ± 0.8 vs 4.2 ± 0.7, p < 0.001), and encouraging critical thinking (4.0 ± 0.7 vs 4.2 ± 0.7, p < 0.001). CONCLUSION The SPs, facilitators, and students had different viewpoints with regards to integrating SPs in the PBL tutorial. However, a majority agreed that this design enhanced the motivation of students and supported such an application in PBL tutorials.
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Su CJ, Pan SW, Huang LJ, Yang LY, Yang YY, Hwang SJ, Chuang CL, Chang CC, Huang HC, Kao SY, Lee FY. Trios-OSCE-based simulation course enhances the subcompetency of emergency-stabilization for postgraduate year-1 residents. J Chin Med Assoc 2019; 82:407-412. [PMID: 31058714 DOI: 10.1097/jcma.0000000000000089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND For patient safety, this study aims to evaluate the effectiveness of additional objective structured clinical examination (OSCE)-based medical simulation courses to establish the "emergency-stabilization" subcompetency of postgraduate first year (PGY-1) residents. METHODS In the simulation course, trainees were randomly divided into three groups: intervention, regular, and control group as Trios-OSCE trainees, Single-OSCE trainees, or OSCE observers (feedback-givers) after attending the pre-OSCE common simulation workshop. Three PGY-1 residents rotated through the Trios OSCE long-station together, while single PGY-1 residents rotated through regular OSCE alone and the control group gave feedback after observation of their peers' OSCE performance. Using Queen's simulation assessment tool, either in Trios-OSCE or Single-OSCE, performance levels were rated as either inferior, novice, competent, advanced or superior in the "therapeutic actions" and "communication" domains. The "overall performances" of all trainees were graded by qualified assessors, experienced facilitators, and standardized senior nurse. RESULTS The proportion of "overall performance" of trainee's, rated by an experienced facilitator as "above competent level," was significantly higher in intervention group A than in regular group B. After training, the degree of increase in self-efficacy scores was higher among the intervention group than the regular and control groups. In the follow-up stage, a trend of increasing self-efficacy scores was noted in both the interventional and regular groups. For all trainees among the three groups, high postcourse value scores confirm that the new Trios-OSCE model meets the needs of trainees and also motivates the self-directed learning and self-reflection of trainees. CONCLUSION Our results provide initial evidence that the new emergency-stabilization-enhanced Trios-OSCE-based medical simulation course including the additional training capacity offered by adding an observer group had positive effects on PGY-1 residents' self-efficacy and clinical transfer.
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Goh SW, Adawiyah J, Md Nor N, Yap F, Ch'ng P, Chang CC. Skin eruption induced by dieting - an underdiagnosed skin disease in Malaysia. MALAYSIAN FAMILY PHYSICIAN : THE OFFICIAL JOURNAL OF THE ACADEMY OF FAMILY PHYSICIANS OF MALAYSIA 2019; 14:42-46. [PMID: 31289632 PMCID: PMC6612274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Prurigo pigmentosa is an inflammatory dermatosis characterized by a pruritic, symmetrically distributed erythematous papular or papulo-vesicular eruption on the trunk arranged in a reticulated pattern that resolves with hyperpigmentation. It is typically non-responsive to topical or systemic steroid therapy. The exact etiology is unknown, but it is more commonly described in the Far East countries. Dietary change is one of the predisposing factors. We report on nine young adult patients with prurigo pigmentosa, among whom five were on ketogenic diets prior to the onset of the eruptions. All cases resolved with oral doxycycline with no recurrence. We hope to improve the awareness of this uncommon skin condition among general practitioners and physicians so that disfiguring hyperpigmentation due to delayed diagnosis and treatment can be avoided.
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Chang CC, Lee WS, Chuang CL, Hsin IF, Hsu SJ, Huang HC, Lee FY, Lee SD. Effect of ivabradine, a funny current inhibitor, on portal hypertensive rats. J Chin Med Assoc 2019; 82:19-24. [PMID: 30839398 DOI: 10.1016/j.jcma.2018.06.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Ivabradine is a funny current inhibitor which is administered to patients with congestive heart failure to reduce their heart rate (HR) and attenuate oxidative stress. Chronic liver diseases are characterized by portal hypertension and hyperdynamic circulation with tachycardia. The present study aimed to investigate the effect of ivabradine on portal hypertension. METHODS Male Sprague-Dawley rats received partial portal vein ligation (PVL) to induce portal hypertension. The PVL rats were randomly allocated to receive either vehicle or ivabradine treatment for 10 days. Then the hemodynamic data were collected. The levels of oxidative stress markers and the mRNA expression of nitric oxide synthase (NOS) were measured in the collateral vessel, the superior mesentery artery and the liver. In addition, the collateral vascular responsiveness to arginine vasopressin (AVP) was examined in the ivabradine-treated and vehicle-treated PVL rats. RESULTS Treatment with ivabradine significantly lowered the HR (174 ± 20 vs. 374 ± 9 beats/min; p < 0.001) and the superior mesentery arterial flow (SMAf) (6.6 ± 0.3 vs. 9.1 ± 0.7 mL/min/100 g BW; p = 0.005) of the PVL rats compared with the control group. The mean arterial pressure, cardiac index, systemic vascular resistance, portal pressure and serum levels of oxidative stress markers were not significantly affected by ivabradine treatment. In addition, the NOS expression and collateral vascular responsiveness to AVP were not significantly influenced by ivabradine treatment, either. CONCLUSION Ivabradine reduced the HR and SMAf in PVL rats, which alleviated the hyperdynamic circulatory state and splanchnic hyperemia of portal hypertension. However, whether these effects would help alleviate portal hypertension-related complications requires further clinical investigations.
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Chuang CL, Chang CC, Hsu SJ, Huang HC, Lee FY, Huang LJ, Lee SD. Endotoxemia-enhanced renal vascular reactivity to endothelin-1 in cirrhotic rats. Am J Physiol Gastrointest Liver Physiol 2018; 315:G752-G761. [PMID: 30095297 DOI: 10.1152/ajpgi.00302.2017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Hepatorenal syndrome (HRS), a severe complication of advanced cirrhosis, is defined as hypoperfusion of kidneys resulting from intense renal vasoconstriction in response to generalized systemic arterial vasodilatation. Nevertheless, the mechanisms have been barely investigated. Cumulative studies demonstrated renal vasodilatation in portal hypertensive and compensated cirrhotic rats. Previously, we identified that blunted renal vascular reactivity of portal hypertensive rats was reversed after lipopolysaccharide (LPS). This study was therefore conducted to delineate the sequence of renal vascular alternation and underlying mechanisms in LPS-treated cirrhotic rats. Sprague-Dawley rats were randomly allocated to receive sham surgery (Sham) or common bile duct ligation (CBDL). LPS was induced on the 28th day after surgery. Kidney perfusion was performed at 0.5 or 3 h after LPS to evaluate renal vascular response to endothelin-1 (ET-1). Endotoxemia increased serum ET-1 levels ( P < 0.0001) and renal arterial blood flow ( P < 0.05) in both Sham and CBDL rats. CBDL rats showed enhanced renal vascular reactivity to ET-1 at 3 h after LPS ( P = 0.026). Pretreatment with endothelin receptor type A (ETA) antagonist abrogated the LPS-enhanced renal vascular response in CBDL rats ( P < 0.001). There were significantly lower inducible nitric oxide synthase (iNOS) expression but higher ETA and phosphorylated extracellular signal-regulated kinase (p-ERK) expressions in renal medulla of endotoxemic CBDL rats ( P < 0.05). We concluded that LPS-induced renal iNOS inhibition, ETA upregulation, and subsequent ERK signaling activation may participate in renal vascular hyperreactivity in cirrhosis. ET-1-targeted therapy may be feasible in the control of HRS. NEW & NOTEWORTHY Hepatorenal syndrome (HRS) occurred in advanced cirrhosis after large-volume paracentesis or bacterial peritonitis. We demonstrated that intraperitoneal lipopolysaccharide (LPS) enhanced renal vascular reactivity to endothelin-1 (ET-1) in cirrhotic rats, accompanied by inducible nitric oxide synthase inhibition, endothelin receptor type A (ETA) upregulation, and subsequent extracellular signal-regulated kinase activation in renal medulla. Pretreatment with ETA antagonist abrogated the LPS-enhanced renal vascular response in common bile duct ligation rats. These findings suggest that further clinical investigation of ET-1-targeted therapy may be feasible in the control of HRS.
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Nicholson A, Berkowitz E, Monge-Camacho H, Brantley D, Garron N, Chang CC, Rinaldi E, Clark MA, Joó B, Kurth T, Tiburzi BC, Vranas P, Walker-Loud A. Heavy Physics Contributions to Neutrinoless Double Beta Decay from QCD. PHYSICAL REVIEW LETTERS 2018; 121:172501. [PMID: 30411940 DOI: 10.1103/physrevlett.121.172501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Indexed: 06/08/2023]
Abstract
Observation of neutrinoless double beta decay, a lepton number violating process that has been proposed to clarify the nature of neutrino masses, has spawned an enormous world-wide experimental effort. Relating nuclear decay rates to high-energy, beyond the standard model (BSM) physics requires detailed knowledge of nonperturbative QCD effects. Using lattice QCD, we compute the necessary matrix elements of short-range operators, which arise due to heavy BSM mediators, that contribute to this decay via the leading order π^{-}→π^{+} exchange diagrams. Utilizing our result and taking advantage of effective field theory methods will allow for model-independent calculations of the relevant two-nucleon decay, which may then be used as input for nuclear many-body calculations of the relevant experimental decays. Contributions from short-range operators may prove to be equally important to, or even more important than, those from long-range Majorana neutrino exchange.
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Hsieh YH, Huang HC, Chang CC, Chuang CL, Lee FY, Hsu SJ, Huang YH, Hou MC, Lee SD. Nucleos(t)ide Analogs Do Not Independently Influence Hepatic Fibrosis and Portal Hypertension beyond Viral Suppression in CBDL-Induced Cirrhotic Rat. J Pharmacol Exp Ther 2018; 367:260-266. [PMID: 30194095 DOI: 10.1124/jpet.118.250431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Accepted: 08/07/2018] [Indexed: 11/22/2022] Open
Abstract
Chronic hepatitis is the major cause of liver cirrhosis and portal hypertension. Several factors affect portal pressure, including liver fibrosis, splanchnic vasodilatation, and pathologic angiogenesis. Nucleos(t)ide analogs (NUCs), the oral antiviral agents, effectively attenuate chronic hepatitis B-related liver cirrhosis and portal hypertension via viral suppression and alleviation of hepatitis. On the other hand, NUCs affect tumor necrosis factor (TNF)-α, vascular endothelial growth factor (VEGF), and nitric oxide, which participate in fibrogenesis, vasodilatation, and angiogenesis. However, whether NUCs independently influence liver fibrosis and portal hypertension beyond viral suppression is unknown. This study thus aimed to evaluate the influences of three frequently used NUCs in rats with nonviral cirrhosis. Male Sprague-Dawley rats received common bile duct ligation (CBDL) to induce cholestatic cirrhosis and portal hypertension. The rats were randomly allocated into four groups, treated by mouth with lamivudine (30 mg/kg per day), entecavir (0.09 mg/kg per day), tenofovir (50 mg/kg per day), or distilled water (vehicle control) from the 15th day after CBDL. On the 29th day, liver cirrhosis- and portal hypertension-related parameters were evaluated. The results showed that chronic NUCs treatment did not affect hemodynamic parameters, plasma TNF-α concentration, and hepatic fibrogenesis protein expressions in rats with nonviral cirrhosis. Though the mesenteric VEGF receptor 2 phosphorylation was downregulated in NUCs-treated groups, the splanchnic angiogenesis was not influenced. In conclusion, lamivudine, entecavir, and tenofovir had no additional effects on liver cirrhosis and portal hypertension in rats with nonviral cirrhosis.
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Huang CC, Hsu HC, Yang LY, Chen CH, Yang YY, Chang CC, Chuang CL, Lee WS, Lee FY, Hwang SJ. Peer-assisted learning model enhances clinical clerk's procedural skills. J Chin Med Assoc 2018; 81:747-753. [PMID: 29779999 DOI: 10.1016/j.jcma.2017.06.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 06/16/2017] [Accepted: 06/20/2017] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Failure to transfer procedural skills learned in a laboratory to the bedside is commonly due to a lack of peer support/stimulation. A digital platform (Facebook) allows new clinical clerks to share experiences and tips that help augment their procedural skills in a peer-assisted learning/teaching method. This study aims to investigate the effectiveness of the innovation of using the digital platform to support the transfer of laboratory-trained procedural skills in the clinical units. METHODS Volunteer clinical clerks (n = 44) were enrolled into the peer-assisted learning (PAL) group, which was characterized by the peer-assisted learning of procedural skills during their final 3-month clinical clerkship block. Other clerks (n = 51) did not join the procedural skills-specific Facebook group and served as the self-directed learning regular group. The participants in both the PAL and regular groups completed pre- and post-intervention self-assessments for general self-assessed efficiency ratings (GSER) and skills specific self-assessed efficiency ratings (SSSER) for performing vein puncture, intravenous (IV) catheter and nasogastric (NG) tube insertion. Finally, all clerks received the post-intervention 3-station Objective Structured Clinical Skills Examination (OSCE) to test their proficiency for the abovementioned three procedural skills. RESULTS Higher cumulative numbers of vein punctures, IV catheter insertions and NG tube insertions at the bedside were carried out by the PAL group than the regular group. A greater improvement in GSERs and SSSERs for medical procedures was found in the PAL group than in the regular group. The PAL group obtained higher procedural skills scores in the post-intervention OSCEs than the regular group. CONCLUSION Our study suggested that the implementation of a procedural skill-specific digital platform effectively helps clerks to transfer laboratory-trained procedural skills into the clinical units. In comparison with the regular self-directed learning group, the peer-assisted learning characteristics of Facebook give additional benefits to the PAL group by enhancing their procedural skills.
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Prouty NG, Roark EB, Mohon LM, Chang CC. Uptake and distribution of organo-iodine in deep-sea corals. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2018; 187:122-132. [PMID: 29452767 DOI: 10.1016/j.jenvrad.2018.01.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 12/18/2017] [Accepted: 01/04/2018] [Indexed: 06/08/2023]
Abstract
Understanding iodine concentration, transport, and bioavailability is essential in evaluating iodine's impact to the environment and its effectiveness as an environmental biogeotracer. While iodine and its radionuclides have proven to be important tracers in geologic and biologic studies, little is known about transport of this element to the deep sea and subsequent uptake in deep-sea coral habitats. Results presented here on deep-sea black coral iodine speciation and iodine isotope variability provides key information on iodine behavior in natural and anthropogenic environments, and its geochemical pathway in the Gulf of Mexico. Organo-iodine is the dominant iodine species in the black corals, demonstrating that binding of iodine to organic matter plays an important role in the transport and transfer of iodine to the deep-sea corals. The identification of growth bands captured in high-resolution scanning electron images (SEM) with synchronous peaks in iodine variability suggest that riverine delivery of terrestrial-derived organo-iodine is the most plausible explanation to account for annual periodicity in the deep-sea coral geochemistry. Whereas previous studies have suggested the presence of annual growth rings in deep-sea corals, this present study provides a mechanism to explain the formation of annual growth bands. Furthermore, deep-sea coral ages based on iodine peak counts agree well with those ages derived from radiocarbon (14C) measurements. These results hold promise for developing chronologies independent of 14C dating, which is an essential component in constraining reservoir ages and using radiocarbon as a tracer of ocean circulation. Furthermore, the presence of enriched 129I/127I ratios during the most recent period of skeleton growth is linked to nuclear weapons testing during the 1960s. The sensitivity of the coral skeleton to record changes in surface water 129I composition provides further evidence that iodine composition and isotope variability captured in proteinaceous deep-sea corals is a promising geochronometer as well as an emerging tracer for continental material flux.
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Dixon PC, Stirling L, Xu X, Chang CC, Dennerlein JT, Schiffman JM. Aging may negatively impact movement smoothness during stair negotiation. Hum Mov Sci 2018; 60:78-86. [PMID: 29843055 DOI: 10.1016/j.humov.2018.05.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 05/17/2018] [Accepted: 05/17/2018] [Indexed: 11/25/2022]
Abstract
Stairs represent a barrier to safe locomotion for some older adults, potentially leading to the adoption of a cautious gait strategy that may lack fluidity. This strategy may be characterized as unsmooth; however, stair negotiation smoothness has yet to be quantified. The aims of this study were to assess age- and task-related differences in head and body center of mass (COM) acceleration patterns and smoothness during stair negotiation and to determine if smoothness was associated with the timed "Up and Go" (TUG) test of functional movement. Motion data from nineteen older and twenty young adults performing stair ascent, stair descent, and overground straight walking trials were analyzed and used to compute smoothness based on the log-normalized dimensionless jerk (LDJ) and the velocity spectral arc length (SPARC) metrics. The associations between TUG and smoothness measures were evaluated using Pearson's correlation coefficient (r). Stair tasks increased head and body COM acceleration pattern differences across groups, compared to walking (p < 0.05). LDJ smoothness for the head and body COM decreased in older adults during stair descent, compared to young adults (p ≤ 0.015) and worsened with increasing TUG for all tasks (-0.60 ≤ r ≤ -0.43). SPARC smoothness of the head and body COM increased in older adults, regardless of task (p < 0.001), while correlations showed improved SPARC smoothness with increasing TUG for some tasks (0.33 ≤ r ≤ 0.40). The LDJ outperforms SPARC in identifying age-related stair negotiation adaptations and is associated with performance on a clinical test of gait.
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Naderi A, Koschella A, Heinze T, Shih KC, Nieh MP, Pfeifer A, Chang CC, Erlandsson J. Corrigendum to "Sulfoethylated nanofibrillated cellulose: Production and properties" [Carbohydr. Polym. 169 (2017) 515-523]. Carbohydr Polym 2018; 179:1. [PMID: 29111030 DOI: 10.1016/j.carbpol.2017.09.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Lai KM, Hsieh MH, Lam F, Chen CY, Chen TL, Chang CC. Anesthesia for patients with tracheal bronchus. Asian J Anesthesiol 2017; 55:87-88. [PMID: 29122588 DOI: 10.1016/j.aja.2017.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 09/26/2017] [Indexed: 06/07/2023]
Abstract
Tracheal bronchus is a congenital anatomical variant of patients with accessory bronchus in the right upper lobe deriving directly from the supracarinal trachea. Pre-operative consultation with the anesthesiologist is important for patient safety and can avoid adverse effects induced by endotracheal intubation. In this report, we described a case of tracheal bronchus in which general anesthesia was performed for video-assisted thoracoscopic surgery. We discussed some of the issues surrounding to complications in tracheal bronchus.
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Cheng TY, Lee WS, Huang HC, Lee FY, Chang CC, Lin HC, Lee SD. The effects of pioglitazone in cirrhotic rats with hepatopulmonary syndrome. J Chin Med Assoc 2017; 80:683-689. [PMID: 28969989 DOI: 10.1016/j.jcma.2017.08.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Revised: 08/16/2017] [Accepted: 06/12/2017] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Hepatopulmonary syndrome (HPS) is characterized by oxygen desaturation and increased intrapulmonary shunting formation in cirrhosis. Due to an unclarified mechanism, there is still no effective therapy except liver transplantation. Recent studies revealed that pulmonary angiogenesis may participate in pathogenesis, in which nitric oxide (NO) and vascular endothelial growth factor (VEGF) play roles. Pioglitazone, a peroxisome proliferator-activated receptor gamma agonist, exerts anti-angiogenesis effect. However, whether pioglitazone influences pulmonary angiogenesis, shunting and HPS remains unexplored. METHODS Cirrhosis with HPS was induced in Spraque-Dawley rats with common bile duct ligation (CBDL). Pioglitazone (10 mg/kg/day, oral gavage) or vehicle was administered from 8th to 28th day post CBDL. On the 28th day, the mortality rate, hemodynamic parameters, concentrations of plasma glucose and liver biochemistry parameters, and arterial blood gas data were evaluated. Lungs were dissected for protein expression analyses. In another series, intrapulmonary shunting degree was determined by color microsphere method in paralleled groups. RESULTS The survival rates were similar in HPS rats with or without pioglitazone administration. Pioglitazone did not influence the hemodynamic parameters, glucose and liver biochemistry levels, oxygen saturation and alveolar arterial gradient, but significantly down-regulated pulmonary VEGF protein expression, endothelial NO synthase (eNOS) activation, and decreased intrapulmonary shunts. Pioglitazone significantly decreased intrapulmonary shunts as compared with the vehicle (18.1 ± 4.5 vs. 9.8 ± 3.6, p = 0.015). CONCLUSION Pioglitazone down-regulated VEGF, eNOS and decreased intrapulmonary shunts without improving oxygenation. The current finding suggests a multifactorial mechanism of HPS that could not be successfully overcome merely by pioglitazone-induced anti-angiogenesis and shunting reduction.
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Faber GS, Koopman AS, Kingma I, Chang CC, Dennerlein JT, van Dieën JH. Continuous ambulatory hand force monitoring during manual materials handling using instrumented force shoes and an inertial motion capture suit. J Biomech 2017; 70:235-241. [PMID: 29157658 DOI: 10.1016/j.jbiomech.2017.10.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 09/20/2017] [Accepted: 10/15/2017] [Indexed: 11/17/2022]
Abstract
Hand forces (HFs) are commonly measured during biomechanical assessment of manual materials handling; however, it is often a challenge to directly measure HFs in field studies. Therefore, in a previous study we proposed a HF estimation method based on ground reaction forces (GRFs) and body segment accelerations and tested it with laboratory equipment: GFRs were measured with force plates (FPs) and segment accelerations were measured using optical motion capture (OMC). In the current study, we evaluated the HF estimation method based on an ambulatory measurement system, consisting of inertial motion capture (IMC) and instrumented force shoes (FSs). Sixteen participants lifted and carried a 10-kg crate from ground level while 3D full-body kinematics were measured using OMC and IMC, and 3D GRFs were measured using FPs and FSs. We estimated 3D hand force vectors based on: (1) FP+OMC, (2) FP+IMC and (3) FS+IMC. We calculated the root-mean-square differences (RMSDs) between the estimated HFs to reference HFs calculated based on crate kinematics and the GRFs of a FP that the crate was lifted from. Averaged over subjects and across 3D force directions, the HF RMSD ranged between 10-15N when using the laboratory equipment (FP + OMC), 11-18N when using the IMC instead of OMC data (FP+IMC), and 17-21N when using the FSs in combination with IMC (FS + IMC). This error is regarded acceptable for the assessment of spinal loading during manual lifting, as it would results in less than 5% error in peak moment estimates.
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Ko HH, Chang CC, Lin CH, Kuo YH, Chen IS, Chang HS. Bioactive chemical constituents isolated from the root of Neolitsea acuminatissima. Am J Transl Res 2017. [DOI: 10.1055/s-0037-1608145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Åmellem I, Suresh S, Chang CC, Tok SSL, Tashiro A. A critical period for antidepressant-induced acceleration of neuronal maturation in adult dentate gyrus. Transl Psychiatry 2017; 7:e1235. [PMID: 28925998 PMCID: PMC5639251 DOI: 10.1038/tp.2017.208] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 06/21/2017] [Indexed: 11/15/2022] Open
Abstract
Selective serotonin reuptake inhibitors (SSRIs) are the most commonly used medications for mood and anxiety disorders, and adult neurogenesis in the dentate gyrus has been shown to be involved in the behavioral effects of SSRIs in mice. Studies have shown the varied effects of chronic treatment with SSRIs on adult neurogenesis. One such effect is the acceleration of neuronal maturation, which affects the functional integration of new neurons into existing neuronal circuitry. In this study, we labeled new neurons by using GFP-expressing retroviral vectors in mice and investigated the effect of an SSRI, fluoxetine, on these neurons at different time points after neuronal birth. Chronic treatment with fluoxetine accelerated the dendritic development of the newborn neurons and shifted the timing of the expression of the maturational marker proteins, doublecortin and calbindin. This accelerated maturation was observed even after sub-chronic treatment, only when fluoxetine was administered during the second week of neuronal birth. These results suggest the existence of a 'critical period' for the fluoxetine-induced maturation of new neurons. We propose that the modified functional integration of new neurons in the critical period may underlie the behavioral effects of fluoxetine by regulating anxiety-related decision-making processes.
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Ko MT, Huang HC, Lee WS, Chuang CL, Hsin IF, Hsu SJ, Lee FY, Chang CC, Lee SD. Metformin reduces intrahepatic fibrosis and intrapulmonary shunts in biliary cirrhotic rats. J Chin Med Assoc 2017; 80:467-475. [PMID: 28676445 DOI: 10.1016/j.jcma.2017.05.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 05/23/2017] [Accepted: 03/27/2017] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Liver fibrosis causes portal hypertension which dilates collateral vasculature and enhances extra-hepatic angiogenesis including intrapulmonary shunts, which subsequently complicates with hepatopulmonary syndrome. Metformin is an anti-diabetic agent which possesses anti-inflammation and anti-angiogenesis properties. This study evaluated the effect of metformin treatment on liver and lung in a non-diabetic rat model with biliary cirrhosis induced via common bile duct ligation (CBDL). METHODS CBDL rats were fed with metformin 150 mg/kg/day during the 8th-28th day post operation. The hemodynamic and biochemistry parameters were tested, and blood gas analysis was performed. The liver and lung were dissected for protein analysis and immuno-histochemical stains. Intrapulmonary shunting degree was determined using color microsphere method. RESULTS Metformin treatment neither induced obvious hypoglycemic event nor altered hemodynamics in cirrhotic rats. The plasma levels of alanine aminotransferase were significantly reduced by metformin (control vs. metformin: 269 ± 56 vs. 199 ± 21 IU/L, P = 0.02). Sirius Red stains and CD-68 stains showed that metformin reduced intrahepatic fibrosis and CD-68-positive macrophages. Metformin did not influence hypoxia and intrapulmonary angiogenesis; however, it significantly reduced intrapulmonary shunts (31.7 ± 10.1 vs. 15.0 ± 6.6%, P = 0.006.). Furthermore, metformin reduced the protein expressions of COX-2 and PI3K in liver and COX-1 in lung. CONCLUSION Metformin reduced liver injury and improved hepatic fibrosis in cirrhotic rats. It also attenuated the intrapulmonary shunts. However, the effects of metformin on pulmonary angiogenesis and hypoxia were insignificant.
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Li HY, Duan Y, Yang BQ, Chang CC, Liu N, Zhang LX, Lin S. [Analysis of the correlation between deep medullary veins and clinical prognosis of middle cerebral artery stroke]. ZHONGHUA YI XUE ZA ZHI 2017; 97:1956-1959. [PMID: 28693074 DOI: 10.3760/cma.j.issn.0376-2491.2017.25.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To investigate the relativity between the distribution of deep medullary vein (DMV) in patients with middle cerebral artery stroke and clinical prognosis by using susceptibility-weighted imaging (SWI). Methods: A total of 144 cases of middle cerebral artery stroke patients and 55 healthy volunteers were retrospectively analyzed from January 2015 to October 2015 in order to investigate the symmetrical characteristic and the classification of DMV, then 30 cases were followed up. Kappa test was used to consider the consistency of judging DMV symmetry and type data by two radiologists. Results:Kappa value in DMV symmetry and DMV type were 0.875 and 0.852. Chi-square test analysis revealed a statistically significant difference of DMV symmetry between healthy control and stroke group(χ(2)=31.046, P=0.000). There was correlation between DMV type and NIHSS score in stroke group (r(s)=0.208, P=0.025). There was no statistically significant difference of DMV distribution in the different periods of stroke group (P=0.110). But there was statistically significant difference of DMV distribution between acute and chronic stroke (P=0.018). Among 30 follow-up cases, 18 cases with asymmetry DMV changed into symmetry after stroke therapy. In 8 cases with symmetry DMV, the diameter of DMV became smaller after treatment. In 4 cases, DMV had no changes. Conclusions: DMV in patients of MCA stroke are mostly asymmetry distribution. DMV classification can be used as an imaging standard to predict the prognosis of stroke patients.
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Duan Y, Yang BQ, Chang CC, Zhou J, Li HY, Xu ZH, Wang ZW, Li DY. [Preliminary study on assessment of lexiscan-induced blood-brain barrier opening and its level by CT perfusion imaging]. ZHONGHUA YI XUE ZA ZHI 2017; 96:2825-2829. [PMID: 27686551 DOI: 10.3760/cma.j.issn.0376-2491.2016.35.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To evaluate the level of lexiscan-induced blood-brain barrier opening of healthy rabbits via CT perfusion weighted imaging (PWI) scan. Methods: Between November 2014 and May 2015, thirty New Zealand white rabbits were randomly assigned into three groups: the experimental group A1 which received one injection of lexiscan(1 ml/kg); the experimental group A2 which received three times injection of lexiscan(total dose: 1.5 ml/kg), finished within 15 minutes; the control group B which was injected the same volume normal saline(1 ml/kg), after 30 minutes, CT PWI scan was performed. Then cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT) and permeability surface(PS) of the region of interest of each group were acquired and compared statistically. Five cases of each group were injected with 2% Evans blue intravenously posterior to imaging. After one hour of infusion, all the animals were killed. Their brains were examined for the determination of Evans blue distribution. Results: Both the values of CBF and CBV and the staining with Evans blue of the group A1(CBF: (89.88±2.21), (81.42±4.28) ml·(100 g)-1·min-1; CBV: (3.97±0.43), (3.66±0.16) ml/g)and group A2 (CBF: (75.16±0.84), (63.66±7.21) ml·(100 g)-1·min-1; CBV: (4.07±0.01), (3.75±0.05) ml/g) were higher than those of the group B(CBF: (20.08±5.08), (14.58±8.62) ml·(100 g)-1·min-1; CBV: (0.85±0.04), (0.65±0.17) ml/g), the differences were all statistically significant (all P<0.01). While there was no statistically difference between group A1 and group A2(P>0.05). The value of PS of the group A2((22.43±8.09), (20.20±7.01)ml·(100 g)-1·min-1 )was higher than that of group A1((13.82±4.44), (10.12±2.44)ml·(100 g)-1·min-1) and group B(0.00, 0.00)(the lowest one), the differences were all statistically significant(all P<0.01). The value of MTT of the group A1((2.50±0.82, 2.47±0.10) s) had no statistical difference with group A2 and group B, while the value of group A2((4.50±0.17), (4.72±0.15) s) was higher than that of group B((1.88±0.09), (1.99±0.00) s), the differences were all statistically significant (P<0.05). Conclusion: Changes in hemodynamics of lexiscan-induced blood-brain barrier opening can be monitored by CT PWI scan. When the total dose of lexiscan increasing, the level of the BBB opening is higher with significantly increased CBF, CBV, PS and MTT.
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Chang CC, Lee WS, Chuang CL, Hsin IF, Hsu SJ, Chang T, Huang HC, Lee FY, Lee SD. Effects of raloxifene on portal hypertension and hepatic encephalopathy in cirrhotic rats. Eur J Pharmacol 2017; 802:36-43. [PMID: 28238769 DOI: 10.1016/j.ejphar.2017.02.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 02/22/2017] [Accepted: 02/22/2017] [Indexed: 01/13/2023]
Abstract
Raloxifene, a selective estrogen receptor modulator, has been used extensively for osteoporosis. In addition to the effect of osteoporosis treatment, emerging evidences show that raloxifene affects the vascular function in different tissues. Cirrhosis is characterized with portal hypertension and complicated with hepatic encephalopathy. Portal hypertension affects portal-systemic shunt which leads to hepatic encephalopathy that the vascular modulation might influence severity of hepatic encephalopathy. Herein, we evaluated the impact of raloxifene on bile duct ligation (BDL)-induced cirrhotic rats. The female Sprague-Dawley rats received BDL plus ovariectomy or sham-operation. Four weeks later, rats were divided into 2 subgroups respectively to receive of raloxifene (10mg/kg/day) or saline (vehicle) for 14 days. On the 43th day, motor activities and hemodynamic parameters were measured. Hepatic and vascular mRNA and protein expressions were determined. The histopathological change of liver was examined. We found that the liver biochemistry, ammonia level and motor activity were similar between cirrhotic rats with or without raloxifene administration. The hemodynamic parameters were not significantly different except that raloxifene reduced portal venous inflow. Raloxifene exacerbated hepatic fibrosis and up-regulated hepatic endothelin-1 and cyclooxygenase 2 protein expressions. In addition, raloxifene modulated the mRNA expressions of endothelial nitric oxide synthase, cyclooxygenase and endothelin-1 in the superior mesenteric artery and collateral vessel. In conclusion, raloxifene aggravates hepatic fibrosis and decreases portal venous inflow in cirrhotic rats without adversely affecting portal hypertension and hepatic encephalopathy. The modulation of hepatic and vascular endothelin-1, endothelial nitric oxide synthase and cyclooxygenase expressions may play a role in the mechanism.
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Chang YS, Chang CC, Chen YH, Chen WS, Chen JH. Risk of infective endocarditis in patients with systemic lupus erythematosus in Taiwan: a nationwide population-based study. Lupus 2017; 26:1149-1156. [PMID: 28420053 DOI: 10.1177/0961203317694260] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Objectives Patients with systemic lupus erythematosus are considered vulnerable to infective endocarditis and prophylactic antibiotics are recommended before an invasive dental procedure. However, the evidence is insufficient. This nationwide population-based study evaluated the risk and related factors of infective endocarditis in systemic lupus erythematosus. Methods We identified 12,102 systemic lupus erythematosus patients from the National Health Insurance research-oriented database, and compared the incidence rate of infective endocarditis with that among 48,408 non-systemic lupus erythematosus controls. A Cox multivariable proportional hazards model was employed to evaluate the risk of infective endocarditis in the systemic lupus erythematosus cohort. Results After a mean follow-up of more than six years, the systemic lupus erythematosus cohort had a significantly higher incidence rate of infective endocarditis (42.58 vs 4.32 per 100,000 person-years, incidence rate ratio = 9.86, p < 0.001) than that of the control cohort. By contrast, the older systemic lupus erythematosus cohort had lower risk (adjusted hazard ratio 11.64) than that of the younger-than-60-years systemic lupus erythematosus cohort (adjusted hazard ratio 15.82). Cox multivariate proportional hazards analysis revealed heart disease (hazard ratio = 5.71, p < 0.001), chronic kidney disease (hazard ratio = 2.98, p = 0.034), receiving a dental procedure within 30 days (hazard ratio = 36.80, p < 0.001), and intravenous steroid therapy within 30 days (hazard ratio = 39.59, p < 0.001) were independent risk factors for infective endocarditis in systemic lupus erythematosus patients. Conclusions A higher risk of infective endocarditis was observed in systemic lupus erythematosus patients. Risk factors for infective endocarditis in the systemic lupus erythematosus cohort included heart disease, chronic kidney disease, steroid pulse therapy within 30 days, and a recent invasive dental procedure within 30 days.
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Tuan PH, Chang CC, Chang FL, Lee CY, Sung CL, Cho CY, Chen YF, Su KW. Modelling end-pumped passively Q-switched Nd-doped crystal lasers: manifestation by a Nd:YVO 4/Cr 4+:YAG system with a concave-convex resonator. OPTICS EXPRESS 2017; 25:1710-1722. [PMID: 29519025 DOI: 10.1364/oe.25.001710] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
A theoretical model for the passively Q-switched (PQS) operation which includes the spatial overlapping between the pump and lasing modes under the thermal lensing effect is developed to give a transcendental equation that can directly determine the critical parameters such as pulse energy, pulse repetition rate, and pulse width for the PQS performance. More importantly, an analytical function which gives the approximate solution for the transcendental equation as well as a specific critical criterion for good PQS operation are derived for practical analyses and design. A Nd:YVO4/Cr4+:YAG system with a concave-convex resonator which can achieve fairly stable PQS pulse trains even at a high pump level is further exploited to manifest the proposed spatially dependent model. The good agreement between the experimental results and the theoretical predictions is verified to show the feasibility of the proposed model for designing high-power PQS lasers with high accuracy.
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