Summary
Biological nitrogen fixation in rhizobia occurs primarily in root or stem nodules and is induced by the bacteria present in legume plants. This symbiotic process has fascinated researchers for over a century, and the positive effects of legumes on soils and their food and feed value have been recognized for thousands of years. Symbiotic nitrogen fixation uses solar energy to reduce the inert N
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gas to ammonia at normal temperature and pressure, and is thus today, especially, important for sustainable food production. Increased productivity through improved effectiveness of the process is seen as a major research and development goal. The interaction between rhizobia and their legume hosts has thus been dissected at agronomic, plant physiological, microbiological and molecular levels to produce ample information about processes involved, but identification of major bottlenecks regarding efficiency of nitrogen fixation has proven to be complex. We review processes and results that contributed to the current understanding of this fascinating system, with focus on effectiveness of nitrogen fixation in rhizobia.
Intracranial aneurysms are present in roughly 5% of the population, yet most are often asymptomatic and never detected. Development of an aneurysm typically occurs during adulthood, while formation and growth are associated with risk factors such as age, hypertension, pre-existing familial conditions, and smoking. Subarachnoid hemorrhage, the most common presentation due to aneurysm rupture, represents a serious medical condition often leading to severe neurological deficit or death. Recent technological advances in imaging modalities, along with increased understanding of natural history and prevalence of aneurysms, have increased detection of asymptomatic unruptured intracranial aneurysms (UIA). Studies reporting on the risk of rupture and outcomes have provided much insight, but the debate remains of how and when unruptured aneurysms should be managed. Treatment methods include two major intervention options: clipping of the aneurysm and endovascular methods such as coiling, stent-assisted coiling, and flow diversion stents. The studies reviewed here support the generalized notion that endovascular treatment of UIA provides a safe and effective alternative to surgical treatment. The risks associated with endovascular repair are lower and incur shorter hospital stays for appropriately selected patients. The endovascular treatment option should be considered based on factors such as aneurysm size, location, patient medical history, and operator experience.
Conventional dissection surgery (CDS) or using the Plastibell device (PD) is the method most frequently employed for circumcision. The aim of this study was to evaluate two methods in terms of the incidence of complications in infants of ages up to 12 months. In a prospective study, 586 infants equal to or less than 12 months were studied from 2002 to 2008, and complications between the two groups were assessed. The overall rates of complications in CDS and PD groups were 1.95% and 7.08%, respectively. In each group, the rate of complications was not different among children who had a normal weight, compared to those of a lower or upper (10%) weight. There was a significant positive correlation between the age and weight of subjects within the time of ring separation (P < .001). The results of this study suggest the PD method for neonates and low-weight infants with thin prepuce and the CDS for other infants.
Background: Aphallia or penile agenesis is a rare malformation accompanying with no phallus. This anomaly is extremely rare with abnormality of urogenital system and psychological consequences. Its outbreak is estimated 1 out of 10-30 million births. Case: Reviewing 3 cases of male external genitalia agenesis, which associated with multiple anomalies of musculoskeletal, cardiovascular and genitourinary system. Conclusion: Aphallia has psychosocial consequences and a guarded prognosis. This study showed that if the kidney failure is due to its obstruction, these patients will be born in more favorable conditions and the future treatment measures will be directed to keep the external genitalia (male) through timely diagnosis and prenatal surgery and timely bladder drainage.
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______________________________________________________________ ______________________Purpose: Tubularized Incised Plate (TIP) urethroplasty is a technique for urethral reconstruction of hypospadias although there are some controversies for its use in recurrent cases. The aim of this study was to review the results of TIP technique in various studies and the usage of different flaps for covering the repair site. Material and Methods: Extensive Search was performed for articles published between 1994 and 2013 in common electronic databases. The overall TIP complication rates were estimated by a fixed effects model meta-analysis.Results: 17 articles of hypospadia repair using the TIP method were reviewed. All studies performed surgery and repair on the basis of the Snodgrass's method; however, some introduced modifications to the method. The prevalence of complications in repeated TIP surgery was 11.1 to 33.3% and the most prevalent complication in different studies was fistula. Based on the meta-analysis, the overall estimation of complications was 21.8 % (95% CI: 18.3 to 25.5).
Conclusion:Most studies performed the incision of the urethral plate to create a supportive coverage upon neourethra, and confirmed its success. We recommend further investigation on using different flaps in well-designed randomized controlled trials to choose the best surgical method for repairing recurrent hypospadias.
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