共查询到13条相似文献,搜索用时 15 毫秒
1.
Function and connectivity in human primary auditory cortex: a combined fMRI and DTI study at 3 Tesla
Upadhyay J Ducros M Knaus TA Lindgren KA Silver A Tager-Flusberg H Kim DS 《Cerebral cortex (New York, N.Y. : 1991)》2007,17(10):2420-2432
Human primary auditory cortex (PAC) is functionally organized in a tonotopic manner. Past studies have used neuroimaging to characterize tonotopic organization in PAC and found similar organization as that described in mammals. In contrast to what is known about PAC in primates and nonprimates, in humans, the structural connectivity within PAC has not been defined. In this study, stroboscopic event-related functional magnetic resonance imaging (fMRI) was utilized to reveal mirror symmetric tonotopic organization consisting of a high-low-high frequency gradient in PAC. Furthermore, diffusion tensor tractography and probabilistic mapping was used to study projection patterns within tonotopic areas. Based on earlier physiological and histological work in nonhuman PAC, we hypothesized the existence of cross-field isofrequency (homotopic) and within-field non-isofrequency (heterotopic)-specific axonal projections in human PAC. The presence of both projections types was found in all subjects. Specifically, the number of diffusion tensor imaging (DTI) reconstructed fibers projecting between high- and low-frequency regions was greater than those fibers projecting between 2 high-frequency areas, the latter of which are located in distinct auditory fields. The fMRI and DTI results indicate that functional and structural properties within early stages of the auditory processing stream are preserved across multiple mammalian species at distinct evolutionary levels. 相似文献
2.
A robust control strategy has been designed for an aircraft during take-off. The effects of different windshear intensities have been analysed for one- and two-dimensional models. The robust control is designed to tolerate windshear regardless of its variations. The only information the control utilizes is the upper-bound value of the allowable control magnitude. 相似文献
3.
Daniel Portalez Pierre Mozer François Cornud Raphaëlle Renard-Penna Vincent Misrai Matthieu Thoulouzan Bernard Malavaud 《European urology》2012
Background
Wide variations in acquisition protocols and the lack of robust diagnostic criteria make magnetic resonance imaging (MRI) detection of prostate cancer (PCa) one of the most challenging fields in radiology and urology.Objective
To validate the recently proposed European Society of Urogenital Radiology (ESUR) scoring system for multiparametric MRI (mpMRI) of the prostate.Design, setting, and participants
An institutional review board–approved multicentric prospective study; 129 consecutive patients (1514 cores) referred for mpMRI after at least one set of negative biopsies.Intervention
Transfer of mpMRI-suspicious areas on three-dimensional (3D) transrectal ultrasound images by 3D elastic surface registration; random systematic and targeted cores followed by core-by-core analysis of pathology and mpMRI characteristics of the core locations. The ESUR scores were assigned after the procedure on annotated Digital Imaging and Communications in Medicine archives.Outcome measurements and statistical analysis
Relationships between ESUR scores and biopsy results were assessed by the Mann-Whitney U test. The Yates correction and Pearson χ2 tests evaluated the association between categorical variables. A teaching set was randomly drawn to construct the receiver operating characteristic curve of the ESUR score sum (ESUR-S). The threshold to recommend biopsy was obtained from the Youden J statistics and tested in the remaining validation set in terms of sensitivity, specificity, positive predictive value, negative predictive value, and accuracy.Results and limitations
Higher T2-weighted, dynamic weighted imaging and dynamic contrast-enhanced ESUR scores were observed in areas yielding cancer-positive cores. The proportion of positive cores increased with the ESUR-S aggregated in five increments (ESUR-S 3–5: 2.9%; ESUR-S 6–8: 11.1%; ESUR-S 9–10: 38.2%; ESUR-S 11–12: 63.4%; and ESUR-S 13–15: 83.3%; p < 0.0001). A threshold of ESUR-S ≥9 exhibited the following characteristics: sensitivity: 73.5%; specificity: 81.5%; positive predictive value: 38.2%; negative predictive value: 95.2%; and accuracy: 80.4%. Although the study was not designed to compare repeat biopsy strategies, more targeted cores than random systematic cores were found to be positive for cancer (36.3% compared with 4.9%, p < 0.00001).Conclusions
In the challenging situation of repeat biopsies, the ESUR scoring system was shown to provide clinically relevant stratification of the risk of showing PCa in a given location. 相似文献4.
Y Moriwaki H Toyoda N Harunari M Iwashita T Kosuge S Arata N Suzuki 《Annals of the Royal College of Surgeons of England》2013,95(1):20-25
Introduction
The usefulness of thoracic damage control (DC) for trauma requiring a thoracotomy is not established. The aim of this study was to clarify the usefulness of thoracic packing as DC surgery.Methods
This was a retrospective case series study of 12 patients with thoracic trauma suffering uncontrollable intrathoracic haemorrhage and shock who underwent intrathoracic packing. Our thoracic DC technique consisted of ligation and packing over the bleeding point or filling gauze in the bleeding spaces as well as packing for the thoracotomy wound. The success rates of intrathoracic haemostasis, changes in the circulation and the volume of discharge from the thoracic tubes were evaluated.Results
Packing was undertaken for the thoracic wall in five patients, for the lung in four patients, for the vertebrae in two patients and for the descending thoracic aorta in one patient. Haemostasis was achieved successfully in seven cases. Of these, the volume of discharge from the thoracic tube exceeded 400ml/hr within three hours after packing in three patients, decreased to less than 200ml/hr within seven hours in six patients and decreased to 100ml/hr within eight hours in six patients. Systolic pressure could be maintained over 70mmHg by seven hours after packing.Conclusions
Intrathoracic packing is useful for some patients, particularly in the space around the vertebrae, at the lung apex, and between the diaphragm and the thoracic wall. After packing, it is advisable to wait for three hours to see whether vital signs can be maintained and then to wait further to see if the discharge from the thoracic tube decreases to less than 200ml/hr within five hours. 相似文献5.
Wu JiWeiwei Ding MD Xingdong LiuXiaomin Kao MD Xingwei XuNing Li MD Jieshou Li MD 《The Journal of surgical research》2014
Background
Temporary bowel ligation (TL) has been proposed to prevent contamination as a damage control procedure in multiple bowel perforations. However, bacteria translocation and intestinal ischemia may develop in a prolonged duration. We here hypothesized that intraintestinal drainage combined with temporary ligation (D-TL) would decrease intestinal injury and improve survivals in a gunshot multiple bowel perforation swine model in the setting of a damage control surgery.Materials and methods
The abdomen was shot one time with an experimental modified gun whereas pigs were hemorrhaged to a mean arterial pressure of 40 mm Hg and maintained in shock for 40 min. Cold lactated Ringer solution was gradually infused to induce hypothermia. Animals were randomized to primary anastomosis, TL and intraintestinal D-TL groups (n = 8). Animals were resuscitated for 12 h with the shed blood and lactated Ringer solution. Delayed anastomosis was performed in TL and D-TL animals after resuscitation. Surviving animals were humanely killed 24 h after operation. Systemic hemodynamic parameters were recorded and blood samples were obtained for biochemical assays. Intra-abdominal pressure, portal vein and peripheral vein bacterial cultures, small intestine hematoxylin-eosin staining, and transmission electron microscopy examination were performed at 0, 2, 6, 12, and 24 h after the surgery.Results
All animals suffered extreme physiologic conditions as follows: hypothermia, severe acidosis, hypotension, and depressed cardiac output. Compared with the primary anastomosis and TL group, D-TL animals required less resuscitation fluid, suffered a lower intra-abdominal hypertension and bacterial translocation, normalized lactate levels faster, had lower serum creatine kinase, aspartate aminotransferase levels and tissue TNF-α level, and nuclear factor-kB activations and thus had greater early survival.Conclusions
Compared with primary intestinal anastomosis and TL, rapid bowel ligation combined with intraintestinal drainage as a damage control adjunct improved survivals in a multiple bowel perforation swine model in the setting of damage control surgery. 相似文献6.
Continuous flow blood pumps, such as axial flow and centrifugal pumps, have been gaining interest as circulatory devices for total artificial hearts (TAHs) because of their smaller size and simpler structure compared to pulsatile pumps. However, continuous flow pumps are more prone to atrial wall suction than pulsatile pumps are. Sudden increases in flow rate to meet changes in physiological demand, especially in the left pump, often cause atrial wall suction. In this study, a control algorithm to prevent atrial wall suction from occurring in the left atrium by controlling the rotational speed of the right pump, instead of reducing the cardiac output of the left pump, was developed and investigated. The method was tested in a mock circulatory system and in acute animal experiments with adult goats. Two centrifugal pumps were used to totally replace the circulatory function of the natural heart. The cardiac output of each pump was determined independently by a control algorithm running on a computer connected through a serial interface to the pump driving units. Results showed that left atrial wall suction could be prevented using this method, and that the method could be performed simultaneously with physiological control of the artificial heart. 相似文献
7.
BACKGROUND: In vitro and experimental studies of mesenchymal-epithelial interaction for the prostatic stroma have demonstrated that the prostatic stroma is capable of inducing the nonprostatic epithelium to acquire many features of prostatic epithelium. We investigated whether this phenomenon could be observed in vivo in human prostatic stroma. MATERIALS AND METHODS Sixty transitional cell carcinoma (TCC) of the urinary bladder: (a) 20 with glandular lumen; (b) 20 without glandular lumen: (c) 10 mixed TCC-adenocarcinoma (ACA); and (d) 10 with synchronous or metachronous TCC of the prostate; and three primary TCC of the prostate were examined and submitted for immunostaining for prostatic acid phosphatase (PAP) and prostatic specific antigen (PSA). RESULTS: There was a spectrum of immunostaining for PSA ranging from negative reactivity in TCC without glandular lumen of the urinary bladder, to focal and weak reactivity in single cells with varying degrees of nonmucinous glandular differentiation and to strong reactivity in groups of cells in primary and synchronous or metachronous TCC in the prostate. The areas of carcinoma geographically closest to the prostate and with the most extensive nonmucinous glandular differentiation displayed the most frequent and strongest immunoreactivity for PSA. The immunoreactivity for PAP was usually stronger than for PSA. Four cases of TCC and mixed TCC-ACA were immunoreactive only for PAP. Furthermore, there was a change in the phenotype of TCC in the urinary bladder as it spread into the prostate. For 10 TCC in the urinary bladder with synchronous or metachronous tumor in the prostate, all TCC in the urinary bladder were negative for PAP and PSA, whereas six TCC in the prostate were focally positive. CONCLUSIONS: The spectrum of immunoreactivity for PAP and PSA and the change in immunoreactivity of TCC of the urinary bladder as it spreads into the prostate are likely induced by the prostatic stroma through the mechanism of mesenchymal-epithelial interaction. Prostate 47:172-182, 2001. 相似文献
8.
Jimena Quinzaños-Fresnedo Paola C. Fratini-Escobar Kievka M. Almaguer-Benavides Ana Valeria Aguirre-Güemez Aída Barrera-Ortíz Ramiro Pérez-Zavala 《The journal of spinal cord medicine》2020,43(3):331-338
Objective: The objective of the present work was to determine the prognostic validity of the trunk control test for walking and independence in individuals with SCI.Design: A cohort, prospective study was carried out in all individuals with sub-acute SCI.Setting: All inpatients at the Mexico City based National Rehabilitation Institute (INR).Participants: Ninety individuals with a clinical diagnosis of sub-acute SCI, American Spinal Injury Association Impairment Scale (AIS) A-D, and that have not participated in a rehabilitation program were included. Thirty-five individuals had good initial trunk control and the remaining 55 had poor trunk control. All individuals participated in a standard rehabilitation program subsequently.Interventions: N/AOutcome Measures: The trunk control test was performed at baseline. At 1, 3, 6, 9 and 12 months after the first evaluation, walking and independence were assessed.Results: Survival Analysis revealed that 62.5% and 100% individuals with good trunk control at baseline assessment were respectively walking and independent in ADL at 12 months and 14% and 48% individuals with poor trunk control were walking and independent in ADL. Cox regression analysis revealed that individuals with good trunk control were 4.6 times more likely to walk independently at 12 months and 2.9 times more likely to be independent in activities of daily living.Conclusion: The present study revealed that the trunk control test is useful for providing a prognosis of independence and walking at 1 year in individuals with SCI, independently of the neurologic level and the severity of the injury. 相似文献
9.
Development of an in vivo visual robot system with a magnetic anchoring mechanism and a lens cleaning mechanism for laparoendoscopic single‐site surgery (LESS)
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Haibo Feng Dinghui Dong Tengfei Ma Jinlei Zhuang Yili Fu Yi Lv Liyi Li 《The international journal of medical robotics + computer assisted surgery : MRCAS》2017,13(4)
10.
Matteo Razzanelli Emanuele Crisostomi Lucia Pallottino Gabriele Pannocchia 《Optimal control applications & methods.》2020,41(1):25-41
This paper deals with the application of model predictive control (MPC) to optimize power flows in a network of interconnected microgrids (MGs). More specifically, a distributed MPC (DMPC) approach is used to compute for each MG how much active power should be exchanged with other MGs and with the outer power grid. Due to the presence of coupled variables, the DMPC approach must be used in a suitable way to guarantee the feasibility of the consensus procedure among the MGs. For this purpose, we adopt a tailored dual decomposition method that allows us to reach a feasible solution while guaranteeing the privacy of single MGs (ie, without having to share private information like the amount of generated energy or locally consumed energy). Simulation results demonstrate the features of the proposed cooperative control strategy and the obtained benefits with respect to other classical centralized control methods. 相似文献
11.
George Kasotakis Michael Duggan Yongqing Li David O'Dowd Keith Baldwin Marc A. de Moya David R. King Hasan B. Alam George Velmahos 《The Journal of surgical research》2013
Background
We previously demonstrated that abdominal gas insufflation (AGI) reduces intra-abdominal bleeding. To date, this is the only method that holds promise for reducing mortality from internal bleeding in a pre-hospital setting. We aimed to assess the optimal AGI pressure and the effectiveness of a portable miniaturized insufflator in abdominal bleeding control.Materials and methods
We randomized 15 Yorkshire swine to receive AGI of 20, 25 or 30 mm Hg after sustaining a standardized severe splenic injury, to determine the ideal pressure for optimal bleeding control. We randomized six (40%) to insufflation with a custom-designed, battery-operated, 7-oz portable CO2 tank, whereas we used a standard laparoscopic insufflator for the remainder. Intravenous fluid boluses were administered as needed to maintain a mean arterial pressure of >60 mm Hg. At 30 min, the animals were re-laparotomized and their hemoperitoneum was quantified.Results
Target peritoneal pressures were achieved and maintained successfully with both insufflation methods. There was a trend toward greater blood loss and fluid requirements in the 30-mmHg group (P = 0.71 and 0.97, respectively). Increasing the AGI led to less predictable blood loss and fluid resuscitation requirements, as well as worsening of tissue perfusion markers (pH and lactate), likely because of iatrogenic abdominal compartment syndrome.Conclusions
All target peritoneal pressures were easily and reliably achieved with the portable CO2 insufflator. Abdominal gas insufflation produced optimal bleeding control at 20 mm Hg. This technology could be used in a pre-hospital setting to control otherwise lethal hemorrhage at pressures typically used for standard laparoscopic surgery and proven to be safe. 相似文献12.
Intrathecal morphine (ITM) for postoperative pain control in children: a comparison with nalbuphine patient controlled analgesia (PCA) 总被引:1,自引:0,他引:1
SUSAN W. KRECHEL MD MARY ALICE HELIKSON MD DIAN KITTLE RN CPAN G.W.N. EGGERS Jr MD 《Paediatric anaesthesia》1995,5(3):177-183
This is a retrospective study covering the ten-year period 1984–1993. Single shot spinal morphine (ITM) is compared with PCA nalbuphine for postoperative pain relief in children having abdominal or thoracic procedures. The records of 52 patients meeting selection criteria were examined. Nursing and physician notations were reviewed for hourly pain assessments, evidence of associated complications, respiratory depression, nausea and or vomiting, pruritus, and urinary retention. ITM provided significantly better pain relief (2.2 h in pain) during the first 24 h postoperatively than PCA nalbuphine (9.2 h in pain). With the exception of urinary retention which was significantly more frequent following ITM (58.6%) compared to PCA nalbuphine (8.7%), narcotic related complications were not different between the two groups. No difference in duration of hospital stay or ICU stay could be demonstrated. We conclude that ITM provides better pain relief, without more serious complications, than PCA nalbuphine. We recommend it as a safe, effective technique to treat postoperative pain in children following thoracic or upper abdominal procedures. 相似文献