RESUMEN
Objective: To investigate the multiple origin of retroperitoneal liposarcoma and its postoperative prognosis. Methods: A total of 49 retroperitoneal liposarcoma patients underwent total (ipsilateral) retroperitoneal lipectomy in our center from May 2017 to December 2019 were recruited. Clinical data and the follow-up information were reviewed and the origin and prognosis were analyzed. Results: A total of 15 patients were pathologically diagnosed as multiple primary cancer (MPC), the incidence rate of retroperitoneal liposarcoma with MPC was 30.6% (15/49), while other 34 cases was non-MPC. The postoperative recurrence rates of patients with high differentiation and de-differentiation retroperitoneal liposarcoma were 31.8% and 44.4%, without significant difference (P>0.05). The postoperative recurrence rates of MPC and non-MPC were 40.0% and 38.2%, without significant difference (P>0.05). Five cases died within the follow-up. Conclusion: Retroperitoneal liposarcoma might origin form MPC, and total (ipsilateral) retroperitoneal lipectomy is recommended to reduce the recurrence rate.
Asunto(s)
Liposarcoma , Neoplasias Primarias Múltiples , Neoplasias Retroperitoneales , Humanos , Liposarcoma/diagnóstico por imagen , Liposarcoma/cirugía , Recurrencia Local de Neoplasia , Pronóstico , Neoplasias Retroperitoneales/diagnóstico por imagen , Neoplasias Retroperitoneales/cirugíaRESUMEN
OBJECTIVE: To investigate the clinical features and outcome of hydronephrosis induced by retroperitoneal fibrosis (RPF), and to evaluate the effect of corticosteroid based therapy combined with surgical intervention of ureteral obstruction. METHODS: A total of 17 RPF patients with hydronephrosis hospitalized in Peking University International Hospital from May 2016 to December 2019 were analyzed retrospectively. RESULTS: The median age was 56 (53, 65) years, the male to female ratio was 2.4 : 1, and the disease duration was 4.00 (0.83, 8.00) months. The initial symptoms included back pain (9 cases), abdominal pain (6 cases), oliguria (2 cases) and lower limb edema (3 cases). Eight patients presented left hydronephrosis, 1 right hydronephrosis and 8 bilateral hydronephrosis. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were both elevated in 13 patients (76.5%, n=17). Immunoglobin (Ig) G4 increased in 5 cases (29.4%, n=17). IgG, IgE and IgA increased in 4 cases (30.8%, n=13), 4 cases (30.8%, n=13) and 1 case (7.7%, n=13), respectively. Among 12 patients who underwent biopsy, 3 patients were diagnosed with IgG4-relate disease. The level of IgG4 in the tissues varied, 6 cases expressed less than 10 per high power field (HPF) or no expression (50.0%). Only 2 cases expressed 10-30/HPF (16.7%), and 4 cases revealed more than 30/HPF (33.3%). Among the 17 patients with ureteral obstruction, no urinary drainage procedure was needed in 4 patients who had mild ureteral obstruction, whereas, ureteral stenting was carried out in the other 13 cases before drug treatment. Time was too short to evaluate the effect of urinary drainage procedures in 4 patients. For the rest, ureterolysis had to be performed in 3 cases after failed ureteral stent insertion. Successful drain removal was accomplished in all of these 9 patients and the mean time to drain removal was (6.7±3.0) months. In addition, 10 patients had complete medical records after an average follow-up time of 5 (3-13) months. Levels of ESR, CRP, IgG4, IgG, IgE, IgA were 54.0 (36.3, 98.5) mm/h, 26.8 (8.7, 53.0) mg/L, 1.34 (0.55, 3.36) g/L, 16.3 (13.0, 21.1) g/L, 40.5 (31.4, 203.0) IU/mL, 2.51 (1.82, 3.25) g/L at baseline, which all decreased predominantly after treatment. ESR, CRP, IgG4, IgG, IgE and IgA dropped by 38.5 (23.5, 54.3) mm/h (P < 0.01), 23.0 (5.5, 52.0) mg/L (P < 0.05), 0.92 (0.40, 2.85) g/L (P < 0.01), 6.5 (1.7, 9.1) g/L (P < 0.05), 23.7 (4.8, 162.0) IU/mL (P < 0.05) and 0.77 (0.32, 1.26) g/L (P < 0.05), respectively. Size of mass measured by CT/MRI imaging became smaller significantly and hydronephrosis relieved. CONCLUSION: Onset of RPF is insidious and lack of specific initial symptoms. Corticosteroid based therapy combined with surgical intervention of relieving obstruction is effective.
Asunto(s)
Hidronefrosis , Fibrosis Retroperitoneal , Uréter , Obstrucción Ureteral , Anciano , Femenino , Humanos , Hidronefrosis/etiología , Masculino , Fibrosis Retroperitoneal/complicaciones , Estudios RetrospectivosRESUMEN
Objective: To evaluate the efficacy of ultrasound guided quadratus lumborum block combined with non-steroidal anti-inflammatory drugs for postoperative analgesia in patients undergoing total hip arthroplasty. Methods: From January to June 2017, sixty American Society of Anesthesiologists (ASA) physical status â to â ¢ patients, aged 55-75 yr, scheduled for total hip arthroplasty, were randomly divided into control group(group N) and quadratus lumborum block (group R). Ultrasound guided quadratus lumborum block was implemented on the affected side at the end of operation.Then 30 ml 0.33% ropivacaine were administrated in group R, while the control group did not receive the same block. A sufentanil patient-controlled analgesia pump was connected to the patient. The rest visual analogue score (VAS) were recorded at 0 h(T(0)), 3 h(T(1)), 6 h (T(2)), 12 h(T(3)), 24 h (T(4)), 36 h (T(5)) and 48 h(T(6)) after sugery, the VAS scores on movement were evaluated at T(4), T(5) and T(6) time points.The consumption of sufentanil within each period time were recorded.The maximal flexion and abduction degrees of the hip joint were evaluated at 12, 24, 36 and 48 h after operation. The number of patients for rescue pain relief by intravenous analgesia pump during 24 h and 48 h after surgery were counted in both groups. The postoperative adverse effects and overall satisfaction in the two groups were recorded. Results: The VAS at rest in group R were 0.8±0.4, 1.0±0.3, 1.2±0.5, 2.0±0.5, 1.7±0.4 , 1.6±0.5 at T(1), T(2), T(3), T(4), T(5), T(6) respectively, and those in group N were 3.0±0.7, 3.5±0.9, 3.8±0.9, 3.3±1.1, 3.3±0.7, 3.0±0.7 at the same time points. The VAS at rest were lower in group R than those in control group at all time points (F=203.090, 216.354, 203.956, 35.548, 96.332, 80.577, all P<0.01). The VAS on movement in group R were 2.7±0.9, 2.9±0.7 , 2.0±0.6 at T(4), T(5), T(6) respectively , and those in group N were 6.0±1.5, 5.8±1.1, 4.5±1.0. The VAS on movement were also lower in group R than those in control group(F=154.561, 143.224, 141.479, all P<0.01). The maximum flexion degrees in group R were (61±12)degrees, (64±10)degrees, (69±15)degrees and(78±19)degrees at 12, 24, 36, 48 h after operation, and those were (45±11) degrees, (49±10)degrees, (52±12)degrees and(60±14)degrees at the same time points. The maximum flexion degrees in group R were increased more than control group at 12, 24, 36, 48 h after operation(F=34.981, 35.575, 52.106, 41.681, all P<0.01). The abduction degrees in group R were(22±6)degrees, (26±6)degrees, (27±8)degrees and(28±7)degrees at 12, 24, 36, 48 h after surgery, and those in group N were (14±5) degrees, (17±6)degrees, (20±6)degrees and(20±5)degrees. The abduction degrees in group R were increased more than those in group N(F=58.974, 33.402, 19.151, 20.575, all P<0.01). The rates of rescue analgesia for pain relief were 10% and 16.7% at 24 h and 48 h after operation respectively in group R, and those were 100% and 100% in group N. Compared to group N, the rates of rescue analgesia for pain relief in group R were significantly decreased (χ(2)=49.091, 42.857, all P<0.01). The incidences of postoperative nausea and vomiting, pruritus in group R were 3.3% and 3.3% respectively, and those in group N were 23.3% and 20.0%. The incidences of nausea and vomiting, pruritus in group R were lower than those in group N (χ(2)=5.192, 4.875, all P<0.01). The overall satisfaction scores in group R (3.7 ± 1.0 ) were higher than those (1.9±0.7) in the group N(t=7.841, P<0.01). Conclusion: The quadratus lumborum block combined with parecoxib sodium for multimodal analgesia after total hip arthroplasty is effective and provides satisfactory analgesia.
Asunto(s)
Manejo del Dolor , Anciano , Analgesia Controlada por el Paciente , Analgésicos Opioides , Anestésicos Locales , Artroplastia de Reemplazo de Cadera , Humanos , Persona de Mediana Edad , Bloqueo Nervioso , Dolor PostoperatorioRESUMEN
Stroke is a non-communicable disease of increasing socioeconomic importance in aging populations. This study compared the risk factors implicated in two subtypes of ischemic stroke: lacunar stroke (LS) and non-lacunar stroke (NLS). A retrospective case control study was conducted on a total of 368 patients [220 cases (59.8%) of NLS and 148 cases (40.2%) of LS] with first-time onset of ischemic stroke. Multivariate logistic regression was performed to compare multiple non-cerebrovascular risk factors between the two groups. More patients with a history of diabetes were found in the NLS than the LS group (40.5 vs 26.4%), and that both fasting glucose and HbA1C levels before the onset of stroke were higher in NLS than LS patients. Multivariate analysis revealed that patients with a history of diabetes were 1.57 times more likely to have NLS than LS (OR = 1.57, 95%CI = 0.95-3.26). Moreover, male patients were more likely to develop NLS than females (OR = 1.46, 95%CI = 0.79-2.69), and patients with elevated fibrinogen levels were 1.4 times more likely to develop NLS than LS (OR = 1.40, 95%CI = 1.09-1.80). Additionally, patients who were heavy drinkers (OR = 1.39, 95%CI = 0.68-2.84) or smokers (OR = 1.62, 95%CI = 0.91-2.89) were more likely to develop NLS than LS. Other risk factors, such as hypertension, dyslipidemia, age, and average blood pressure, did not differ between the two types of stroke. Thus, distinct non-cerebrovascular risk factors (male gender, long history of diabetes, elevated fibrinogen, heavy smoking, and heavy drinking) are associated with a higher risk of developing non-lacunar stroke than lacunar stroke.
Asunto(s)
Isquemia Encefálica/complicaciones , Accidente Vascular Cerebral Lacunar/etiología , Accidente Cerebrovascular/etiología , Anciano , Consumo de Bebidas Alcohólicas/efectos adversos , Glucemia/metabolismo , Estudios de Casos y Controles , Complicaciones de la Diabetes/sangre , Complicaciones de la Diabetes/etiología , Dislipidemias/complicaciones , Ayuno/sangre , Femenino , Fibrinógeno/metabolismo , Hemoglobina Glucada/metabolismo , Humanos , Hipertensión/complicaciones , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Estudios Retrospectivos , Factores de Riesgo , Factores Sexuales , Fumar/efectos adversos , Accidente Cerebrovascular/sangre , Accidente Vascular Cerebral Lacunar/sangreRESUMEN
The scaly-sided merganser (Mergus squamatus), found in temperate East Asia, has been reduced to a very small population. Central and southern China are its main wintering habitat. However, populations have declined greatly since the 1980s due to habitat loss and degradation, and poaching. To meet the urgent need for up-to-date conservation information, we examined RAPD DNA markers from 156 specimens in 6 populations in Jiangxi Province. We found that genetic diversity (based on individual similarities) is in fact low; molecular variance between populations ranged from 0.137 to 0.347. Genetic similarity ranged from 0.683 to 0.866. In conclusion, the geographical pattern of genetic diversity supports the long-term refugial status of the scaly-sided merganser in central-southern China; strong conservation measures should be taken to maintain the merganser in this region.
Asunto(s)
Anseriformes/genética , Marcadores Genéticos/genética , Variación Genética , Técnica del ADN Polimorfo Amplificado Aleatorio , Animales , China , Ecosistema , Especies en Peligro de Extinción , Genética de PoblaciónRESUMEN
AIM: The effect of race on Crohn's disease (CD) remains uncertain. This study compared the characteristics of American white patients and Chinese patients with CD. METHOD: A retrospective chart review was conducted for patients who required management of colorectal CD between 1985 and 2004 at either Cleveland Clinic Florida (CCF) or at the 301 Hospital in China. Data included a family history of CD, smoking history, location of the CD and histopathology. RESULTS: The mean age of onset in the 153 patients was 29.8 ± 16.4 years for American white patients and 32.4 ± 15.3 years for Chinese patients (not significant). Sixty per cent of American white patients were women vs 37% of Chinese patients (P = 0.003). Twelve per cent of American white patients vs 1% of Chinese patients had a family history of CD (P = 0.016). American white patients had significantly higher rates of arthritis (32%vs 4%), abscess (19%vs 0%), rectal and perineal fistula (52%vs 0%), and disease involving the colon and rectum when compared with Chinese patients (all P < 0.05). American white patients had more colorectal sites involved and higher rates of extraintestinal diseases (40%vs 20%) than Chinese patients (all P < 0.05). Chinese patients had higher rates of ileocaecal disease (82%vs 52%) and deep ulcers (66%vs 24%) in the colorectum (all P < 0.001). There were no statistical differences in the incidence of smoking, perforation, intra-abdominal fistula, stenosis, bowel obstruction, toxic megacolon or granuloma formation. CONCLUSION: This study found that colorectal CD had a more severe clinical presentation and pathological involvement in American white patients than in Chinese patients.
Asunto(s)
Enfermedad de Crohn/patología , Enfermedad de Crohn/fisiopatología , Absceso/complicaciones , Adulto , Artritis/complicaciones , Pueblo Asiatico , Enfermedad de Crohn/complicaciones , Femenino , Humanos , Masculino , Fístula Rectal/complicaciones , Estudios Retrospectivos , Fumar/efectos adversos , Estados Unidos , Población BlancaRESUMEN
AIM: This prospective study was designed to assess the feasibility of local anaesthesia for LigaSure haemorrhoidectomy in an outpatient setting. METHOD: From April 2006 to March 2007, 207 consecutive patients (median age 42, 126 males) with grade III (147) and grade IV (60) haemorrhoids, underwent Milligan-Morgan haemorrhoidectomy with LigaSure under local anaesthesia (lidocaine 1%, mean dose 27 +/- 1.7 ml) in an outpatient setting. Postoperative pain was assessed by a visual analogue scale (VAS). RESULTS: Two, three and four files were removed in 120, 51 and 36 patients. Mean operative time was 12 +/- 5.2 min and mean blood loss was 3.4 +/- 3.9 ml. The mean postoperative pain scores were 6.2 +/- 2.1 for the maximal pain intensity and 6.1 +/- 2.5 for the pain on defecation. All patients left hospital after surgery within 2 h and 33 (15.9%) required analgesics. They returned to normal daily activity after 12.2 +/- 7.9 days including work (12.1 +/- 7.8 days). The wounds had healed by 32.2 +/- 9.1 days. At a follow-up of at least 6 months, only six cases of major bleeding had occurred and 24 patients had skin tags. The median satisfaction score was +2 (-2 to +3). CONCLUSION: LigaSure haemorrhoidectomy under local anaesthesia in the outpatient setting is safe and effective.
Asunto(s)
Procedimientos Quirúrgicos Ambulatorios , Anestésicos Locales/administración & dosificación , Electrocoagulación , Hemorroides/cirugía , Lidocaína/administración & dosificación , Adulto , Femenino , Humanos , Inyecciones Intramusculares , Masculino , Persona de Mediana Edad , Bloqueo Nervioso , Satisfacción del Paciente , Cicatrización de HeridasRESUMEN
Objective: To understand the discovery of human brucellosis cases in new affected counties in Sichuan province, 2015-2017, and provide evidences for prevention and control of human brucellosis. Methods: The incidence data and outbreak data of human brucellosis in Sichuan were collected from Chinese Infectious Disease Surveillance Reporting System, and face to face interview, telephone interview and on-line survey were conducted to collect the case information, such as epidemiological characteristics, medical care seeking. Results: The incidence of human brucellosis in Sichuan has increased obviously since 2013, and 103 counties reported human brucellosis cases for the first time. A total of 23 cases of human brucellosis were investigated, and the common symptoms of the cases was fever, accounting for 91.30% (21/23). The cases mainly sought medical care in hospitals under county-level for the first time, accounting for 73.91% (17/23), and the misdiagnosis rate was 91.30% at the first diagnosis (21/23). The median interval between onset and diagnosis was 52 days, and the longest one was 142 days. Only 4.35% (1/23) cases knew human brucellosis, and when they contacted with suspected livestock, the use rate of protective clothing was 30.43% (7/23), the use rate of gloves was 8.70% (2/23), the use rate of mask was 4.35% (1/23), and the rate of washing hands with disinfectant after contact with livestock was 4.35% (1/23). Goat was suspected to be the infection source of all the cases, and 34.75% (8/23) of the cases were from Gansu, Qinghai and other provinces. The overall awareness rate of human brucellosis in the doctors was 34.58% (102/295), and the training rate was 58.31% (172/295). Only 33.33% (11/33) of the hospitals could perform laboratory diagnosis of human brucellosis and 34.78% (8/23) of county CDCs could carry out laboratory test of human brucellosis. Conclusions: The prevention and control of human brucellosis is facing challenge in Sichuan. The misdiagnosis rate was very high in newly affected counties, and the diagnosis were delayed obviously. The awareness of human brucellosis was low in the cases, and their awareness of self-protection was poor. The awareness rate about human brucellosis in doctors was low and they need more training; the capacity of brucellosis laboratory diagnosis in hospitals and CDCs at county-level should be improved.
Asunto(s)
Brucelosis/diagnóstico , Brucelosis/epidemiología , Brotes de Enfermedades/prevención & control , Brucelosis/prevención & control , China/epidemiología , Notificación de Enfermedades , Conocimientos, Actitudes y Práctica en Salud , Humanos , Incidencia , Médicos/psicologíaRESUMEN
Retained fetal membranes (RFM) of cows is an important reproductive disturbance, and is related to miRNA-185. Stromal interaction molecule 1 (STIM1), a potential target gene of miRNA-185, could influence placenta release via regulating Ca2+ concentration intracellular. The aim of this study was to explore the mechanism of RFM by investigating the regulatory relationship between miRNA-185 and STIM1 in primary uterine caruncel epithelial (UCE) cells. Serum samples of healthy Holstein dairy cows (nâ¯=â¯20) and RFM cows (nâ¯=â¯12), with a similar age, parity, weight, and milk yield, were collected to detect Ca2+ concentration at prepartum 1-5 d and postpartum 6, 12 and 24 h. Caruncle tissues were collected from healthy (n = 6) and RFM cows (n = 6) at 12 h after calving. Quantitative polymerase chain reaction (Q-PCR) and western blotting (WB) were performed to detect the mRNA and protein levels of STIM1, respectively. UCE cells were cultured by the explant culture method, further purified, and subsequently treated with PmirGLO-STIM1-Mut + miRNA-185 mimics and mirGLO-STIM1-Mut + miRNA-185 NC. Q-PCR and WB were performed to detect mRNA and protein levels of STIM1 with treated miRNA-185 mimics. Serum levels of Ca2+ from RFM cows were abnormally decreased at prepartum 1â¯d and postpartum 6, 12 and 24â¯h. Expression level of STIM1 was down-regulated in the caruncle tissue of RFM cows. The luciferase activity was decresed about 30.9% by miRNA-185 mimics (pâ¯<â¯0.01), and the mRNA and protein levels of STIM1 were downregulated miRNA-185-mimics. It was suggesting that miRNA-185 might play an important role in RFM through regulating the expression of STIM1.
Asunto(s)
Enfermedades de los Bovinos/genética , Bovinos/genética , MicroARNs/fisiología , Enfermedades Placentarias/veterinaria , Molécula de Interacción Estromal 1/genética , Animales , Calcio/sangre , Bovinos/fisiología , Enfermedades de los Bovinos/patología , Femenino , Regulación de la Expresión Génica , MicroARNs/genética , MicroARNs/metabolismo , Enfermedades Placentarias/genética , Enfermedades Placentarias/patología , Embarazo , Molécula de Interacción Estromal 1/metabolismo , Molécula de Interacción Estromal 1/fisiologíaRESUMEN
Retention of fetal membranes (RFM) of cows is an important reproductive disturbance, and is related to miRNAs. Vascular endothelial growth factor (VEGF)A, regulated by miRNA-185, can activate arachidonic acid (ARA) release via the VEGFA signaling pathway, which influences RFM. The aim of this study was to explore the pathogenic mechanism of RFM by investigating the regulatory relationship between miRNA-185 and the VEGFA signaling pathway. Serum samples of healthy Holstein dairy cows (n = 20) and RFM cows (n = 12), with a similar age, parity, weight, and milk yield, were collected to detect VEGFA and ARA concentrations at 6, 12, and 24 h after calving. Caruncle tissues were collected from healthy (n = 6) and RFM cows (n = 6) at 12 h after calving. Quantitative polymerase chain reaction (qPCR) and western blotting (WB) were performed to detect the mRNA and proteins levels, respectively, of genes involved in the VEGFA signaling pathway. Uterine caruncle epithelial (UCE) cells were cultured by the explant culture method, further purified, and subsequently treated with miRNA-185 mimics, miRNA-185 mimics + MEK inhibitor, or left untreated as a control for detection of the mRNA and protein levels of genes involved in the VEGFA signaling pathway. The cellular supernatant was collected for measurement of ARA levels at 12, 24 and 48 h after treatment. Serum levels of VEGFA and ARA from RFM cows were abnormally increased at 12 h after calving, as compared to those in healthy dairy cows. Expression levels of most of the investigated genes (VEGFA, PLC, PRK, RAF, MEK, MAPK, and PLA) were down-regulated in the caruncle tissue of RFM cows. However, P-p44/42 MAPK was up-regulated in the caruncle tissues of cows with RFM (pâ¯<â¯.01). In UCE cells treated with the miRNA-185 mimics, expression of VEGFA, PLC, RAF, MEK, MAPK and PLA was significantly down-regulated, while that of P-p44/42 MAPK was significantly up-regulated. Expression of genes involved in the VEGFA signaling pathway was similar to that in the in vivo assay. In UCE cells treated with the miRNA-185 mimics + MEK inhibitors, expression of VEGFA, PLC, RAF, MEK, MAPK and P-p44/42 MAPK was significantly down-regulated, while that of PLA was significantly up-regulated. Meanwhile, the release of ARA was increased (pâ¯<â¯.01). These results demonstrate that miRNA-185 can regulate the VEGFA signaling pathway, especially via abnormal expression of P-p44/42 MAPK, which influences the release of the fetal placenta after calving.
Asunto(s)
Bovinos , MicroARNs/fisiología , Retención de la Placenta/genética , Factor A de Crecimiento Endotelial Vascular/genética , Animales , Bovinos/genética , Bovinos/metabolismo , Enfermedades de los Bovinos/genética , Enfermedades de los Bovinos/metabolismo , Células Cultivadas , Industria Lechera , Membranas Extraembrionarias/metabolismo , Membranas Extraembrionarias/patología , Femenino , Regulación de la Expresión Génica , Sistema de Señalización de MAP Quinasas/fisiología , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Retención de la Placenta/metabolismo , Retención de la Placenta/patología , Embarazo , Transducción de Señal/genética , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Although the indirect calorimeter is a useful tool, its size and expense mean that it is seldom used in hospitals. Furthermore, its flow-through measurement technique dilutes respiratory variations, so they can only be detected with some form of high-precision instrumentation. This study employs MEMS techniques to develop an oxygen sensor as one part of a microscopic energy consumption measurement system, which measures respiration dynamics in a real time manner. The oxygen sensor comprises a polysilicon resistor and a Li-doped (2 wt%) tin-oxide sensing film attached to a thermally isolated silicon-nitride membrane. The power consumption of the sensor is less than 25 mW at an operating temperature of 150 degrees C. Furthermore, it measures oxygen concentrations between 25 and 85% with a linear output response. These characteristics render the proposed sensor suitable for use within a microscopic energy consumption measurement system in either hospital or homecare environments.
Asunto(s)
Técnicas Biosensibles/instrumentación , Calorimetría/instrumentación , Electroquímica/instrumentación , Oximetría/instrumentación , Consumo de Oxígeno/fisiología , Oxígeno/análisis , Animales , Técnicas Biosensibles/métodos , Calorimetría/métodos , Electroquímica/métodos , Diseño de Equipo , Análisis de Falla de Equipo , Gases/análisis , Humanos , Miniaturización/métodos , Oximetría/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Transistores ElectrónicosRESUMEN
High-resolution electron microscopy of amorphous interlayers (a-interlayer) formed by solid-state diffusion between metal thin films and silicon is reviewed. In this paper, an overview of the development is presented. Pertinent data obtained on the growth kinetics and structure of a-interlayers in polycrystalline metal thin films on single-crystal silicon are reported. For the Ti/Si, Zr/Si, Hf/Si, V/Si, Nb/Si and Ta/Si systems, the growth of a-interlayer was found to follow a linear law in the initial stage. Si atoms were found to be the dominant diffusing species in the solid phase amorphization in the Ti/Si, Zr/Si, and Hf/Si systems. For the Y/Si system, the stability of amorphous interlayer depends critically on the composition of the amorphous films. Auto-correlation function analysis was utilized to determine the structure of the amorphous interlayers. HRTEM in conjunction with the fast Fourier transform were applied to determine the first nucleated crystalline phase. Simultaneous presence of multiphases was observed to occur in a number of refractory metal/Si systems.
Asunto(s)
Metales/química , Microscopía Electrónica , Silicio/química , Metales de Tierras Raras/química , Microscopía Electrónica/instrumentaciónRESUMEN
Recently, an ultrasensitive, optical-fiber-based force transducer was developed to measure the microscopic force of contraction of single heart cells. Since force in cardiac muscle is length and velocity dependent, it is desirable to maintain a constant (isometric) cell length. The original design permits approximately 1% shortening of cell length to occur during twitch contractions. The shortening can be reduced significantly by adding a piezoelectric bimorph actuator and closed-loop control, as described in this paper. As a result, the effective stiffness of the transducer can be increased by a factor of about 100, and cell shortening reduced to approximately 0.01%. For the force probes typically used, this is equivalent to a movement of less than 20 nm for a typical value of 100 nN peak cell force in single frog ventricular cells. The gain in stiffness is obtained without sacrificing sensitivity, although at the expense of frequency response. The new design also permits control of cell length and is applicable to studies of the mechanical stiffness of cardiac cells.
Asunto(s)
Contracción Isotónica/fisiología , Contracción Miocárdica/fisiología , Transductores , Animales , Rana pipiensRESUMEN
A mathematical model of the membrane action potential of a ventricular cardiac cell is used to examine the cellular responses to premature stimulation. Results demonstrate the importance of the slow recovery of INa in determining the response of the cell. Simulated responses to periodic stimulation include monotonic Wenckebach patterns and alternans in APD at normal [K]O. At low [K]O, nonmonotonic Wenckebach periodicities, aperiodic patterns, and enhanced supernormal excitability that results in unstable responses ("chaotic activity") are observed. These observations are consistent with recent experimental results, and the simulations provide insights into the underlying mechanisms at the level of membrane ionic channel kinetics.
Asunto(s)
Modelos Cardiovasculares , Función Ventricular , Potenciales de Acción/fisiología , Animales , Embrión de Pollo , Estimulación Eléctrica , Cobayas , Ventrículos Cardíacos/citología , PeriodicidadRESUMEN
In order to determine the seroprevalence of Toxocara spp. infection in children from Chengdu, we performed an enzyme-linked immunosorbent assay (ELISA) and sandwich ELISA (S-ELISA) with excretory-secretory antigens isolated from second-stage larvae of Toxocara canis (TES-Ag ELISA). The seroprevalences of T. canis antibodies in the children from rural areas, urban districts, and urban districts with recent Ascaris lumbricoides infection were 17.7% (59/333), 2.1% (4/186), and 2.6% (1/38), respectively. Among 63 suspected patients with symptoms of T. canis infection, 31 had positive antibodies. The inhibition assay showed an apparent inhibiting capacity of TES-Ag for the antibody against T. canis larvae. The result of S-ELISA demonstrated that circulating antigens of T. canis larvae could be detected in part of the serum with positive antibodies and that the detection rate for circulating antigens in the sera could be improved by polyethylene glycol-acid treatment. This is the first epidemiological study to confirm the existence of T. canis infection and Toxocara-larvae migrans in Chengdu by the combination of TES-Ag ELISA and S-ELISA.
Asunto(s)
Anticuerpos Antihelmínticos/sangre , Antígenos Helmínticos/sangre , Larva Migrans Visceral/epidemiología , Toxocara canis/inmunología , Toxocara canis/aislamiento & purificación , Toxocariasis/epidemiología , Animales , Niño , Preescolar , China/epidemiología , Perros , Ensayo de Inmunoadsorción Enzimática/métodos , Humanos , Larva Migrans Visceral/diagnóstico , Larva Migrans Visceral/parasitología , Población Rural , Estudios Seroepidemiológicos , Toxocariasis/diagnóstico , Toxocariasis/parasitología , Población UrbanaRESUMEN
BACKGROUND/AIMS: Electrochemical therapy is an alternative to treat hepatoma. We compare this method with the other local injection methods on rat liver. METHODOLOGY: Five groups of Wister rats (24 in each) were anaesthetized. Electrochemical therapy was set under direct current, 6 volts, electrodes were 0.5 cm apart, 0.5 cm deep into exposed parenchyma for 10 min. Local injection was done with 50 microL of 95% alcohol, 30 microL of 20% acetic acid, 30 microL of 35% hydrochloric acid, and 30 microL of 20% sodium hydroxide via a 27-gauge needle under direct vision into each rat. Rats and their livers were examined postmortem on day 1, 3, 7 and 14. RESULTS: In electrochemical therapy, the treated area showed coagulation necrosis and without blood cells on day 1; then the margin became blurred. Mononuclear cell infiltration, reperfusion and fibrous band formation were prominent from day 3 through day 14. In local injection groups, the necrosis is quite irregular and unpredictable. The regeneration went under similar process. CONCLUSIONS: To destroy tissue locally, electrochemical therapy is unique for its predictability in destructive area and the recovery process and is as effective as the other injection methods. Therefore, it has great potential for hepatoma treatment.
Asunto(s)
Terapia por Estimulación Eléctrica/métodos , Neoplasias Hepáticas Experimentales/terapia , Ácido Acético/administración & dosificación , Animales , Etanol/administración & dosificación , Ácido Clorhídrico/administración & dosificación , Inyecciones , Hígado/efectos de los fármacos , Hígado/patología , Neoplasias Hepáticas Experimentales/patología , Ratas , Ratas Wistar , Hidróxido de Sodio/administración & dosificaciónRESUMEN
Single-switch communication is an effective auxiliary method for persons with disabilities. However, it is not easy to recognize the Morse codes typed by them. In our earlier proposed Morse code auto-recognition method, using the Least-Mean-Square (LMS) adaptive algorithm, it was demonstrated that the system could successfully recognize the Morse-coded messages at unstable typing speeds. However, the speed variation had to be limited to a range between 0.67 and two times the present speed. In the case of beginners or those with heavy disabilities, this rule can not always be complied with, producing a low recognition rate of 20%. To address this limitation, this paper offers an advanced recognition method which combines the Least-Mean-Square algorithm with a character-by-character matching technique. The recognition rate for this method from simulated and real data from various sources is as high as 75% or more on average. This practical application of the single-switch method means a step forward toward alternative communication for disabled persons.
Asunto(s)
Algoritmos , Equipos de Comunicación para Personas con Discapacidad , Procesamiento de Señales Asistido por Computador/instrumentación , Programas Informáticos , Humanos , Análisis de los Mínimos CuadradosRESUMEN
A Morse code auto-recognition system is limited by stable typing speed and stable typing ratio from long to short intervals. For an unstable Morse code typing pattern, the auto-recognition algorithms in the literature are not good enough for applications. This paper adopted a neural network to recognize unstable Morse codes. From an experiment on a teenager with cerebral palsy, the neural network has an average recognition rate up to 93.2%. The recognition rate from an amputee aged 40, who used a prosthesis for typing, it is 97.2% on average. When we compare this to 99.2% for the recognition rate from a skilled expert, the result is quite promising. The neural network has successfully overcome the difficulty of analysing a severely unstable Morse code time series. Since the human typing speed is quite slow in comparison to signal processing by the computer, it also makes it possible to use a neural network for real-time signal recognition.
Asunto(s)
Equipos de Comunicación para Personas con Discapacidad , Redes Neurales de la Computación , Adolescente , Adulto , Amputados , Parálisis Cerebral , Computadores , Humanos , Aprendizaje , Reconocimiento de Normas Patrones AutomatizadasRESUMEN
It is generally known that Morse code is an efficient input method for one or two switches and it is made from long and short sounds separated by silence between the sounds. The long-to-short ratio in the definition is always 3 to 1, but the long-to-short ratio variation for a disabled person is so large that it is difficult to recognize. In the last few years, several Morse code recognition methods have been successfully built on the LMS adaptive algorithms and neural network algorithm. But LMS-related adaptive algorithms need mass computation to infer the characteristic of the controller; also the neural network must learn first, by inputting some data before it is used to recognize the Morse code sequence. In this study, two fuzzy algorithms are used to recognize the unstable Morse code sequences and the result demonstrates a significant improvement of recognition for real time signal processing in a single-chip microprocessor.
Asunto(s)
Algoritmos , Equipos de Comunicación para Personas con Discapacidad , Lógica Difusa , Procesamiento de Lenguaje Natural , Reconocimiento de Normas Patrones Automatizadas , Procesamiento de Señales Asistido por Computador , Adolescente , Adulto , Parálisis Cerebral/rehabilitación , Humanos , Control de Calidad , Valores de Referencia , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
There have been several researches on the relationship between music and human physiological or psychological responses. However, there are cardiovascular index factors that have not been explored quantitatively due to the qualitative nature of acoustic stimuli. This study proposes and demonstrates an experimental design for quantification of cardiovascular responses to music stimuli in humans. The system comprises two components: a unit for generating and monitoring quantitative acoustic stimuli and a portable autonomic nervous system (ANS) analysis unit for quantitative recording and analysis of the cardiovascular responses. The experimental results indicate that the proposed system can exactly achieve the goal of full control and measurement for the music stimuli, and also effectively support many quantitative indices of cardiovascular response in humans. In addition, the analysis results are discussed and predicted in the future clinical research.