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排序方式: 共有770条查询结果,搜索用时 15 毫秒
1.
Krishna Pillai Javid Akhter Terence C. Chua Mena Shehata Nayef Alzahrani Issan Al-Alem David L. Morris 《Medicine》2015,94(9)
Thermal ablation of liver tumors near large blood vessels is affected by the cooling effect of blood flow, leading to incomplete ablation. Hence, we conducted a comparative investigation of heat sink effect in monopolar (MP) and bipolar (BP) radiofrequency ablation (RFA), and microwave (MW) ablation devices.With a perfused calf liver, the ablative performances (volume, mass, density, dimensions), with and without heat sink, were measured. Heat sink was present when the ablative tip of the probes were 8.0 mm close to a major hepatic vein and absent when >30 mm away. Temperatures (T1 and T2) on either side of the hepatic vein near the tip of the probes, heating probe temperature (T3), outlet perfusate temperature (T4), and ablation time were monitored.With or without heat sink, BP radiofrequency ablated a larger volume and mass, compared with MP RFA or MW ablation, with latter device producing the highest density of tissue ablated. MW ablation produced an ellipsoidal shape while radiofrequency devices produced spheres.Percentage heat sink effect in Bipolar radiofrequency : Mono-polar radiofrequency : Microwave was (Volume) 33:41:22; (mass) 23:56:34; (density) 9.0:26:18; and (relative elipscity) 5.8:12.9:1.3, indicating that BP and MW devices were less affected.Percentage heat sink effect on time (minutes) to reach maximum temperature (W) = 13.28:9.2:29.8; time at maximum temperature (X) is 87:66:16.66; temperature difference (Y) between the thermal probes (T3) and the temperature (T1 + T2)/2 on either side of the hepatic vessel was 100:87:20; and temperature difference between the (T1 + T2)/2 and temperature of outlet circulating solution (T4), Z was 20.33:30.23:37.5.MW and BP radiofrequencies were less affected by heat sink while MP RFA was the most affected. With a single ablation, BP radiofrequency ablated a larger volume and mass regardless of heat sink. 相似文献
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Tinghu Kang Yang Li Jiandong Guo Xingwen Ma Fatema Akhter Hiramoni Md Zahir Ahmed Mary C. Jobe Oli Ahmed 《International Journal of Mental Health Promotion, The》2022,24(2):207-217
The aim of the study was to explore the relationship between college graduates’ dual self-consciousness, job search
clarity and perceived stress, and reveal the mediating role of perceived stress between dual self-consciousness and
job search clarity. In this study, 467 college graduates were investigated using the Dual Self-Consciousness Scale,
Job Search Clarity Scale, and Perceived Stress Scale. After controlling for gender, age, and region, the results
revealed that: (1) private self-consciousness has a significant positive predictive effect on job search clarity; (2)
perceived stress has a significant negative predictive effect on job search clarity; (3) perceived stress plays partial
mediation effects between private self-consciousness and job search clarity; (4) perceived stress plays complete
mediation effects between public self-consciousness and job search clarity; (5) perceived stress has suppressing
effects between public self-consciousness and job search clarity. 相似文献
4.
Mohammed Akhter M.D. Thomas Z. Lajos M.D. Gary Grosner M.D. Jacob Bergsland M.D. Tomas A. Salerno M.D. 《Journal of cardiac surgery》1997,12(4):210-214
A bstract The right gastroepiploic artery (RGEA) has been utilized as the bypass conduit on the inferior surface of the heart with a minimally invasive approach. Fourteen patients had reoperative coronary bypass surgery for severely symptomatic single-vessel disease of the right coronary artery. All surgeries were performed since May 1996. A small mid-line incision including splitting of the lower sternum gave excellent exposure. The inferior surface of the heart was dissected to expose and stabilize the target vessel. The heart rate was controlled with a diltiazem drip. Cardiopulmonary bypass was not necessary in any case. The right coronary artery was bypassed in three patients, the posterior descending artery branch in ten patients, and the terminal circumflex of the left coronary artery in one. After grafting, patency of the anastomosis was demonstrated by Doppler echocardiogram. Two patients had left anterior descending artery (LAD) grafts with LIMA (left mammary artery) and RGEA grafts performed simultaneously with two port access incisions. No patient had perioperative mortality or complications. No patient had recurrent angina. Doppler color echocardiographic imaging studies before discharge confirmed patency of the graft in 13 of 14 cases. In one case, the gastroepiploic artery could not be visualized. Angiographic visualization was positive in seven cases; seven patients were not studied yet. The gastroepiploic artery is an excellent conduit for vascularization of the inferior aspect of the heart. The operation can be done with a minimally invasive technique and without the use of cardiopulmonary bypass. This approach seems especially applicable in selective reoperative cases. 相似文献
5.
Dekker C Uthaipibull C Calder LJ Lock M Grainger M Morgan WD Dodson GG Holder AA 《Molecular and biochemical parasitology》2004,137(1):143-149
Blood-stage malaria vaccine candidates include surface proteins of the merozoite. Antibodies to these proteins may either block essential steps during invasion or render the merozoite susceptible to phagocytosis or complement-mediated degradation. Structural information on merozoite surface proteins complexed to antibodies provides crucial information for knowledge-based vaccine design. The major merozoite surface protein MSP1 is an abundant surface molecule in Plasmodium falciparum. Only a subset of antibodies against MSP119 inhibits invasion (inhibitory antibodies), whereas other antibodies binding to MSP119 have no effect on invasion (neutral antibodies). Here we report on the complex of MSP119 with both inhibitory monoclonal antibody 12.10 and neutral monoclonal antibody 2F10. The complexes were established using both whole IgG's and Fab fragments, and analysed by dynamic light scattering, electron microscopy and analytical ultra centrifugation. Specific ring structures were formed in the ternary complex with the two antibodies, providing direct evidence of non-overlapping epitopes on MSP119. Mutational studies also indicated that the epitopes of the inhibitory and neutral antibodies are spatially remote. 相似文献
6.
Islam A Vladutiu AO Donahue T Akhter S Sands AM Ambrus JL 《Archives of pathology & laboratory medicine》2000,124(9):1361-1363
The expression of CD8, a restricted T-cell antigen, on B cells in B chronic lymphocytic leukemia is rare, and its significance, if any, remains unknown. We report herein a patient with B chronic lymphocytic leukemia in whom CD8 was strongly expressed on all B cells, both in the bone marrow and peripheral blood. The patient required no therapy for 6 years after being diagnosed as having B chronic lymphocytic leukemia. Then, when the disease progressed, he was treated with conventional doses of fludarabine phosphate (25 mg/m(2) daily for 5 days), but unlike other patients with B chronic lymphocytic leukemia he tolerated this therapy poorly. He received a total of only 4 series of fludarabine therapy, and following each course of treatment, he developed considerable myelosuppression. After the fourth course of therapy, his bone marrow failed to show any evidence of regeneration, and he died as a result of intercurrent respiratory tract infection 1 month after his last dose of fludarabine was given. 相似文献
7.
Akhter MP Iwaniec UT Covey MA Cullen DM Kimmel DB Recker RR 《Calcified tissue international》2000,67(4):337-344
The purpose of this study was to assess breed-related differences in bone histomorphometry, bone biomechanics, and serum
biochemistry in three mouse breeds shown to differ in bone mineral density (BMD) (as measured by DXA) and bone mineral content
(BMC). Femurs, tibiae, and sera were collected from 16-week-old C3H/HeJ {C3H}, C57BL/6J {BL6}, and DBA/2J {DBA}mice (n = 12/breed).
Data collected included BMC and BMD (femora), histomorphometry of cancellous (distal femur) and cortical bone (diaphyseal
tibiae and femora), bone strength (femora), and serum alkaline phosphatase (ALP). Consistent with previous reports, BMC and
BMD were higher in C3H than in BL6 or DBA mice. The higher BMD in the C3H breed was associated with greater cancellous bone
volume, cortical bone area, periosteal bone formation rate, biomechanical strength, and serum ALP. However, mid-diaphyseal
total femoral and tibial cross-sectional area and moment of inertia were greatest in BL6, intermediate in C3H, and lowest
in DBA mice. The specific distribution of cortical bone in C3H, BL6, DBA mice represents a difference in adaptive response
to similar mechanical loads in these breeds. This difference in adaptive response may be intrinsic to the adaptive mechanism,
or may be intrinsic to the bone tissue material properties. In either case, the bone-adaptive response to ordinary mechanical
loads in the BL6 mice yields bones of lower mechanical efficiency (less stiffness per unit mass of bone tissue) and does not
adapt as well as that of the C3H mice where the final product is a bone with greater resistance to bending under load. We
suggest that the size, shape, and BMD of the bone are a result of breed-specific genetically regulated cellular mechanisms.
Compared with the C3H mice, the lower BMD in BL6 mice is associated with long bones that are weaker because the larger cross-sectional
area fails to compensate completely for their lower BMD and BMC.
Received: 16 November 1999 / Accepted: 19 April 2000 / Online publication: 27 July 2000 相似文献
8.
Iwaniec UT Fung YK Cullen DM Akhter MP Haven MC Schmid M 《Calcified tissue international》2000,67(1):68-74
Limited research in young adults and immature animals suggests a detrimental effect of tobacco on bone during growth. This
study investigated the effects of nicotine, the major alkaloid component of tobacco, on calciotropic hormone concentrations
and bone status in growing female rats. One-month-old animals received either saline (n = 10), nicotine at 3.0 mg/kg/day (n
= 10), or nicotine at 4.5 mg/kg/day (n = 10) administered subcutaneously via osmotic minipumps for either 2 or 3 months. Sera,
femora, tibiae, and lumbar vertebrae (3–5) were collected at necropsy. The concentrations of serum calcium, phosphorus, 25-hydroxyvitamin
D, 1,25-dihydroxyvitamin D, parathyroid hormone, calcitonin, and insulin-like growth factor-I were determined. Bone variables
evaluated included mineral content and density (vertebrae and femora), cancellous and cortical histomorphometry (tibiae),
and bone strength (vertebrae and femora). Statistically significant differences in serum mineral and hormone concentrations
were not associated with nicotine dose or exposure time. No significant nicotine treatment effects were detected for bone
mineral content and density, bone histomorphometry, or bone strength. We conclude that nicotine treatment for 2 or 3 months
at serum concentrations in the upper range of those found in smokers has no detrimental effect on bone mass, volume, or strength
in the growing rat.
Received: 20 May 1999 / Accepted: 21 January 2000 相似文献
9.
10.
This urban community clinic had poor asthma outcomes compared to the state of Minnesota. The standard of care supports an annual Asthma Action Plan (AAP). However, the majority of patients at this clinic had not received one. This quality improvement project aimed to improve asthma control, measured by an asthma control test of at least 20, through AAP implementation supported by all team members. The clinic’s interdisciplinary champion group implemented workflow changes via practice facilitation and Plan-Do-Study-Act cycles. Asthma control rates increased from 23% to 58% in adults and 45% to 63% in children over one year, a statistically significant change. 相似文献