We describe how to conduct a regression analysis for competing risks data. The use of an add-on package for the R statistical software is described, which allows for the estimation of the ...semiparametric proportional hazards model for the subdistribution of a competing risk analysis as proposed by Fine and Gray. J Am Stat Assoc 1999; 94: 496-509.
Purpose The purpose of this Guideline is to provide a clinical framework for the diagnosis and treatment of male urethral stricture. Materials and Methods A systematic review of the literature using ...the Pubmed, Embase, and Cochrane databases (search dates 1/1/1990 to 12/1/2015) was conducted to identify peer-reviewed publications relevant to the diagnosis and treatment of urethral stricture. The review yielded an evidence base of 250 articles after application of inclusion/exclusion criteria. These publications were used to create the Guideline statements. Evidence-based statements of Strong, Moderate, or Conditional Recommendation were developed based on benefits and risks/burdens to patients. Additional guidance is provided as Clinical Principles and Expert Opinion when insufficient evidence existed. Results The Panel identified the most common scenarios seen in clinical practice related to the treatment of urethral strictures. Guideline statements were developed to aid the clinician in optimal evaluation, treatment, and follow-up of patients presenting with urethral strictures. Conclusions Successful treatment of male urethral stricture requires selection of the appropriate endoscopic or surgical procedure based on anatomic location, length of stricture, and prior interventions. Routine use of imaging to assess stricture characteristics will be required to apply evidence based recommendations, which must be applied with consideration of patient preferences and personal goals. As scientific knowledge relevant to urethral stricture evolves and improves, the strategies presented here will be amended to remain consistent with the highest standards of clinical care.
In the last decade with widespread use of quantitative analyses in medical research, close co-operation between statisticians and physicians has become essential from the experimental design through ...all phases of complex statistical analysis. On the other hand, easy-to-use statistical packages allow clinicians to perform basic statistical analyses themselves. Since the software they most commonly use does not perform in depth competing risk analysis, we recommend an add-on package for the R statistical software. We provide all the instructions for downloading it from internet and illustrate how to use it for analysis of a sample dataset of patients who underwent haematopoietic stem cell transplantation for acute leukaemia.
Management of iatrogenic ureteral injury Burks, Frank N.; Santucci, Richard A.
Therapeutic Advances in Urology,
06/2014, Letnik:
6, Številka:
3
Book Review, Journal Article
Recenzirano
Odprti dostop
Iatrogenic injury to the ureter is a potentially devastating complication of modern surgery. The ureters are most often injured in gynecologic, colorectal, and vascular pelvic surgery. There is also ...potential for considerable ureteral injury during endoscopic procedures for ureteric pathology such as tumor or lithiasis. While maneuvers such as perioperative stenting have been touted as a means to avoid ureteral injury, these techniques have not been adopted universally, and the available literature does not make a case for their routine use. Distal ureteral injuries are best managed with ureteroneocystostomy with or without a vesico-psoas hitch. Mid-ureteral and proximal ureteral injuries can potentially be managed with ureteroureterostomy. If the distal segment is unsuitable for anastomosis then a number of techniques are available for repair including a Boari tubularized bladder flap, transureteroureterostomy, or renal autotransplantation. In rare cases renal autotransplantation or ureteral substitution with gastrointestinal segments may be warranted to re-establish urinary tract continuity. Laparoscopic and minimally invasive techniques have been employed to remedy iatrogenic ureteral injuries.
Amyloid-beta (Abeta) peptide is commonly found in human Alzheimer's disease (AD) brain and is the main component of Alzheimer amyloid plaques. The predominant forms of Abeta in the human brain are ...Abeta(1-40) and Abeta(1-42), but Abeta(25-35) fragment, physiologically present in elderly people, is the more toxic region and has been recently found to play a relevant role in AD, due to its peculiar aggregation properties. In this work, we review the current understanding on the conformations and biological activity of Abeta(25-35) exploring aggregation, cytotoxic and neurodegenerative properties of this fundamental Abeta fragment, in order to provide an effective starting point to better approach a pathology spread and problematic as AD.
The novel paradigm of distributed energy production foresees the production of hydrogen from methane and biomasses in small plants, which may take advantage from membrane-based processes. By means of ...a modeling approach, this paper compares the energy efficiency of two membrane-based processes to produce H2 from methane steam reforming. The two-step process (TS) envisages a high temperature classical reactor and a following WGS stage in a membrane reactor, while the alternative process uses a simple packed-bed membrane reactor (MR). Both processes show a general increase of H2 production and energy efficiency with the pressure and a maximum energy efficiency for S/C of 4, while the increase of the space velocity reduces the performances of the MR. The results show that the TS process performs better than the studied MR and that the maximum energy efficiency of both processes is between 30 and 40%. A comparison with the literature shows that the TS process may achieve similar performances respect to an intensified MR.
•Two membrane processes for H2 production via methane steam reforming are studied.•The reforming is assessed at T = 650–900 °C, P = 3–15 bar, S/C = 3–12.•Maximum hydrogen yield reaches 80%; Energy efficiency is between 30% and 39%.•Two-Step process generally performs better than packed bed membrane reactor.•Results agree with experimental and modeling studies from literature.
The pressure-composition absorption isotherms of deuterium in an alloy with nominal composition V85Ni15 were measured between 87 and 400 °C for pressures up to ≈17 bar. For T ≤ 144 °C one observes ...the occurrence of a solid solution α phase for D/M < 0.15, the coexistence of α and β phase up to D/M ≈ 0.5 and a subsequent change to a different phase for higher deuterium concentrations. For temperatures higher than 200 °C only a solid solution with a deuteration enthalpy ΔHdeutr = 47 ± 2 kJ/mol is detected. The critical temperature of this V-Ni alloy (144 °C ≤ T*≤200 °C) is much higher than that of pure V (100 °C). Moreover, well above the critical temperature, one can observe a “normal” isotope effect, i.e. the equilibrium pressure of the V85Ni15-H system is higher than that of V85Ni15-D.
•Deuterium absorption in V85Ni15.•Occurrence of α and β phase below 144 °C.•Only a α phase above 200 °C (ΔHdeutr = 47 ± 2 kJ/mol).•Normal isotope effect (the equilibrium pressure in V85Ni15-H system is higher than in V85Ni15-D).
Vaginoplasty tips and tricks Li, Joy S; Crane, Curtis N; Santucci, Richard A
International Brazilian Journal of Urology,
03/2021, Letnik:
47, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Vaginoplasty is a commonly performed surgery for the transfeminine patient. In this review, we discuss how to achieve satisfactory surgical outcomes, and highlight solutions to common complications ...involved with the surgery, including: wound separation, vaginal stenosis, hematoma, and rectovaginal fistula. Pre-operative evaluation and standard technique are outlined. Goal outcomes regarding aesthetics, creation of a neocavity, urethral management, labial appearance, vaginal packing and clitoral sizing are all described. Peritoneal vaginoplasty technique and visceral interposition technique are detailed as alternatives to the penile inversion technique in case they are needed to be used. Post-operative patient satisfaction, patient care plans, and solutions to common complications are reviewed.
The first in this series of five papers concerns the evaluation and management of renal injuries. The authors of this paper come from four continents and seven countries, and they reviewed all papers ...on renal injury published between 1966 and April 2002. The results of the authors’ deliberations are present here as a consensus document.
OBJECTIVE
To determine the optimal evaluation and management of renal injuries by review of the world's English‐language literature on the subject.
METHODS
A consensus conference convened by the World Health Organization and the Societé Internationale d’Urologie met to critically review reports of the diagnosis and treatment of renal trauma. The English‐language literature about renal trauma was identified using Medline, and additional cited works not detected in the initial search obtained. Evidence‐based recommendations for the diagnosis and management of renal trauma were made with reference to a five‐point scale.
RESULTS
There were many Level 3 and 4 citations, few Level 2, and one Level 1 which supported clinical practice patterns. Findings of nearly 200 reviewed citations are summarized.
CONCLUSIONS
Published reports on renal trauma still rely heavily on expert opinion and single‐institution retrospective case series. Prospective trials of the most significant issues, when possible, might improve the quality of evidence that dictates the behaviour of practitioners.
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