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The program aims to build and develop a high-quality donation system at the hospital and national level. Thirty coordinator posts for the transplantation of kidneys from living donors (LDs) were created. The coordinators' tasks were identified as determining or excluding the possibility of LD donation for kidney transplantation for every potential kidney recipient referred to the waiting list, qualifying potential LDs, supervising health monitoring for LDs and kidney recipients, and education and promotion of transplantation from LDs. The coordinators' reports and verification of data in the national transplant register from June 1, 2018 to November 30, 2019 were analyzed. The study was conducted according to principles of the Declaration of Helsinki, and the Declaration of Istanbul participation was on a voluntary basis. Information on possible LDs was obtained from 707 (43%) of the 1630 potential recipients entered on the waiting list. In 373 cases there was no potential LD; 16 recipients did not give consent for kidney transplantation from a LD; for 318 recipients, 340 potential LDs were identified; 90 potential LDs were rejected at the initial stage for medical reasons; 60 potential donors were rejected at further stages of the qualification process; 3 persons resigned from donation; and 23 recipients were transplanted from deceased donors. Kidneys from 73 LDs were qualified and transplanted. On November 30, 2019, 91 potential donors were awaiting further qualification. As part of the program, 27 potential pairs for paired kidney exchange were reported to Poltransplant (17 pairs with positive HLA crossmatch, 10 with incompatible blood groups). The creation of posts for coordinators for LD kidney transplantation in centers that qualify for LD kidney transplantation enabled systematic monitoring of donation potential, which led to an increase in the number of LD kidney transplants in 2019. Making full use of donation potential should significantly increase these numbers in the coming years. • The rate of kidney transplantation from living donors (LDs) in Poland is still very low (1.3 per million population). • The main goal of the program was to build and introduce a quality system of kidney donation from LDs at the hospital level. • The tactical objectives of the program were to build a national network of coordinators for LD kidney transplantation. [ABSTRACT FROM AUTHOR]

An important aspect of band gap engineering in 2D thin films of topological insulators is determining their surface electronic properties at various atomic terminations. In this work, the electronic structure evolution of thin films of bismuth telluride ( [ABSTRACT FROM AUTHOR]

A noticeable effort has been put into developing a consistent understanding of surface electronic structure of topological insulators. Of special interest has been a fundamental feature of their surface electronic states being insensitive to various types of defects and distortions. In the following paper, based on the density functional theory calculations, these topological states are investigated in asymmetric thin films of bismuth selenide with one surface modified by structural distortions. It is shown that the energetics and spatial localisation of the topological electronic states on the modified surface of the film evolve drastically as a consequence of their topological dangling bond nature. It is also shown that all the asymmetric slabs exhibit suppression of the thin film size effect and restoration of massless Dirac electrons on the undistorted surface of the film. The results are relevant for effective band gap engineering in thin films of topological insulators by means of chemical or physical functionalisation. [ABSTRACT FROM AUTHOR]

The age of a donor and recipient is one medical criterion in the kidney allocation system. The number of elderly donors and recipients is steadily growing. The aim of the study was to retrospectively evaluate the 5-year results of kidney transplantation from donors over 65 years of age to recipients over 60 years of age. In the years 1998 to 2010, 8526 potential deceased donation after brain death organ donors and 8206 people (81%), who had been treated with transplantation of kidneys were referred to the Poltransplant. The actual number of deceased donors >65 years was 358 and <65 years was 7207. The actual 5-year survival of a kidney transplant from donors >65 years was 59.2% (55.3% of recipients >60 years and 60.7% of recipients <60 years of age; P < .0001) and from donors <65 years was 75.1% (67.5% of recipients >60 years and 75.7% of recipients <60 years; P < .0001). The actual 5-year survival of kidney recipients from all donors >65 years was 75.6% (79.5% younger recipients vs 65.9% elderly recipients; P < .0001). The 5-year survival of kidney recipients from all donors <65 years was 88.1% ( P < .0001); 89% younger recipients and 74.3% elderly recipients ( P < .0001). The above analysis of the material from the Polish registry displayed significantly worse results of kidney transplantation from donors >65 years, regardless of the age group of recipients. [ABSTRACT FROM AUTHOR]

The aim of the work was to present data concerning organ donation from and transplantation to foreigners in Poland. Data came from registries maintained by the Polish Transplant Coordinating Center POLTRANSPLANT, consisting of the national waiting list, deceased donor registry, transplant registry, and live donor registry. In Poland, the rules for organ and tissue procurement for transplantation from foreigners who died in Poland and the rules for transplanting organs to foreigners are adopted and applied. Before the outbreak of the war in Ukraine, "cross-border" cases of donations and transplants were rather sporadic. After the outbreak of the war, due to the mass influx of Ukrainian citizens, the situation changed, and the participation of foreigners (mostly Ukrainians) in transplantation procedures increased significantly and, in 2022, accounted for the total number of events: approximately 4% in the case of donation, slightly over 1% in the case of qualifications for transplantation and almost 2% in the number of transplantations performed. Despite this increase, the number of events is not high or critical and does not affect the efficiency of organ transplantation medicine in Poland., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: In this paper, we present organ donation and transplantation activities in Poland from 2017 to 2022. Data came from registries maintained by the Polish Transplant Coordinating Center Poltransplant and consisted of the national waiting list, deceased donor registry, transplant registry, and the live donor registry. Poltransplant is the Competent Authority in Organs, with tasks related to preparing assessments, analyses, information, and reports in transplantation medicine and publishing and disseminating these results in the country and abroad. Poltransplant edits the Poltransplant Bulletin on its web pages and presents its activities at Polish Transplantation Society congresses, published consecutively as professional papers., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: This study aimed to determine the number of recipients with active transplants under the care of transplant centers in 2022 and the current volume and needs for continuous and long-term care in this group of transplant recipients. Data came from the organ transplant registry, one of the registries maintained by the Polish Transplant Coordinating Center Poltransplant. We included recipients of individual organs who, on January 1, 2022, were living with an active transplant performed in previous years and recipients who received a transplant in 2022. The number of recipients under the care of transplant centers in 2022 was 20,994 (55% of all transplants performed in Poland since the beginning of activity in 1966)., Competing Interests: Declaration of competing interest All the authors declare no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Background: This article summarizes comprehensive information about the current status of organ donation and transplantation in Poland., Material and Methods: Reported statistical data of solid organs and vascularized composite allograft donation and transplantation from both deceased and living donors in Poland in 2015-2020 (presented in tables according to selected variables) are based on the national transplant registries, gathering information on donation and transplantation activity in medical centers involved in donation and transplantation programs in Poland., Results: In 2020 during the COVID-19 pandemic, 529 potential deceased donors were referred to the Polish Transplant Coordinating Centre Poltransplant; 1310 solid organs from 393 actual deceased donors (10.2 per million population) were procured, mostly kidneys (758), livers (285), and hearts (157). Eighty percent were multiorgan retrievals (314). In 2020, 1231 organs procured from deceased donors and 59 organs from living donors were transplanted to 1236 recipients., Conclusion: This overview indicates that donation and transplantation activity from deceased donors in Poland decreased about 20% in 2020 compared with 2019, which is comparable with worldwide rates. As the unprecedented pandemic situation affected donation and transplantation procedures, there are measures that must to be taken to return to prepandemic donation and transplantation rates in both deceased and living transplant programs and then continue to improve in the years to come., (Copyright © 2022. Published by Elsevier Inc.)

Background: One of the important tasks of a modern hospital, in addition to treatment, prevention, and education, is the activity in the field of donating organs from deceased and living donors. In July 2010, the Polish Transplantation Coordination Center Poltransplant (the national transplantation organization and the authority responsible for organ donation and transplantation), thanks to the funds of the Ministry of Health, under the National Program for the Development of Transplant Medicine, initiated the project of building a network of coordinators by employing hospital transplantation coordinators in selected hospitals, where it is possible to identify potential deceased donors, perform the brain death diagnostic procedure, and where the conditions are met and it is possible to collect organs (they have an intensive care unit and operating theater in their structures). In Poland, these conditions are met by 388 hospitals with a donation potential., Aim: The aim of the work is to present the functioning of the system of transplant coordinators in Poland., Results: The work presents the system of employment and tasks of transplant coordinators at various levels: hospital coordinators for donating organs from deceased donors, living donation and transplant coordinators, coordinators of hematopoietic cell collection and transplantation, central coordinators of Poltransplant, and organ procurement and transplant coordinators associated with transplant centers., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: In 2006 the National Transplants Registry administered by national transplant organization was introduced in Poland to monitor the results of organ transplantations. Statistical analysis is published yearly in the Poltransplant Bulletin, publicly available on the website and reported to European institutions. The transplant registry cooperates with other registers functioning online, based on the tool https://rejestrytx.gov.pl/. We present the formal analysis of data collected for the years 1996-2019., Materials and Methods: Analysis covered the total number of organ transplantations in every transplant center; outcomes are related to recipients living with a functioning graft 1, 5, and 10 years after transplantation; results presented are real, not extrapolated., Results: The total number of deceased-donor kidney transplantations was 20,606, the 1-year survival rate of recipients with a functioning graft was 90% (data completeness of 97%), and the 10-year survival rate was 59% (data completeness of 99%). The total number of deceased-donor liver transplantations was 4790; the 1-year survival rate of recipients with a functioning graft was 59% (data completeness of 98%)., Summary: The National Transplant Registry is an important tool for quality and safety systems in the transplantation field on the national level. The registry efficiently and effectively fulfills its tasks related to collecting records of all transplantations performed. Monitoring function for graft and recipient survival is also satisfied. The data provide an important and unique source of information to be used by transplant institutions and referred to in the literature., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Ultrathin transition metal oxide films exhibit unique physical and chemical properties not observed for the corresponding bulk oxides. These properties, originating mainly from the limited thickness and the interaction with the support, make those films similar to other supported 2D materials with bulk counterparts, such as transition metal dichalcogenides. Ultrathin iron oxide (FeO) films, for example, were shown to exhibit unique electronic, catalytic and magnetic properties that depend on the type of the used support. Ag(111) has always been considered a promising substrate for FeO growth, as it has the same surface symmetry, only ~5% lattice mismatch, is considered to be weakly-interacting and relatively resistant to oxidation. The reports on the growth and structure of ultrathin FeO films on Ag(111) are scarce and often contradictory to each other. We attempted to shed more light on this system by growing the films using different preparation procedures and studying their structure using scanning tunneling microscopy (STM), low energy electron diffraction (LEED) and X-ray photoelectron spectroscopy (XPS). We observed the formation of a previously unreported Moiré superstructure with 45 Å periodicity, as well as other reconstructed and reconstruction-free surface species. The experimental results obtained by us and other groups indicate that the structure of FeO films on this particular support critically depends on the films' preparation conditions. We also performed density functional theory (DFT) calculations on the structure and properties of a conceptual reconstruction-free FeO film on Ag(111). The results indicate that such a film, if successfully grown, should exhibit tunable thickness-dependent properties, being substrate-influenced in the monolayer regime and free-standing-FeO-like when in the bilayer form.

Objectives: Although the results of endopyelotomy for ureteropelvic junction (UPJ) stenosis are well known, our objective was to study the specific complications of treatment of UPJ stenoses by Acucise balloon., Material and Methods: The specific complications of 50 patients (40 women, 10 men) treated consecutively by Acucise balloon endopyelotomy for UPJ stenosis from January 1994 to February 1999 were reviewed. The mean age was 47 years (range: 19-84 years). Thirty-five stenoses (70%) were primary. A polar pedicle was diagnosed by preoperative CT angiography in 5 cases. The endopyelotomy technique was that described by Chandhokf except in 3 cases in which section with strict external lateral orientation was performed., Results: Mean operating time and mean length of hospital stay were 70 min (range: 35-180 min) and 5.4 days (range: 2-27 days), respectively. Six (12%) technical incidents were observed intraoperatively (3 cases of rupture of balloon) and 7 (14%) haemorrhagic incidents were observed perioperatively (5 polar pedicles). There were no conversions to open surgery. There were 4 (8%) major perioperative complications, all haemorrhagic, which required 2 radiological embolizations and one lumbotomy. Only these patients required transfusion (3.25 units/patient). Fourteen urinary tract infections were observed, including 2 cases of pyelonephritis (4%) and one case of septicaemia (2%). Nine patients experienced severe discomfort due to the double J stent. With a mean follow-up of 47 months, the overall success rate was 74%, not influenced by the development of a complication. Seven (58%) of the 12 patients with failure of endopyelotomy had a lower pole pedicle., Conclusion: Acucise endopyelotomy is a simple and effective technique. However, rigorous indications and technique are essential due to the possibility of haemorrhagic complications, often related to a lower pole vessel.

Objectives: Prosthetic surgery for impotence has been transformed by the use of inflatable prostheses, superseding the old semi-rigid designs. Our objective is to report the functional results and the complications of this type of surgery., Methods: 80 inflatable prostheses were implanted between October 1987 and October 1994. The mean follow-up was 3 years and assessment of the objective (mechanical functioning of the prosthesis and complications) and subjective results (sexuality of the patients) was made in 68 patients., Results: There were: 54.5% functional disturbances, 7% infections, and 27.5% prosthesis removals. Most of the patients were satisfied, although only 65% returned to regular sexual activity., Conclusions: The choice between an inflatable and a semi-rigid prosthesis should be carefully discussed because of the frequent mechanical complications that have been reported for the sophisticated designs. Inflatable penile prostheses nevertheless remain the design of choice. Their reliability has been increasing since the manufacture of monobloc designs. Such a device is costly, and should be compared with that of intracavernous injections.

Prosthetic surgery for impotence has been transformed by the development of inflatable prostheses in the place of older semirigid models. Despite the popularity of this new technique, it raises certain questions concerning the functional results and complications of this surgery, which have only occasionally been studied concomitantly in the literature. The sexuality of patients has generally been evaluated on the basis of answers to a questionnaire sent to the patients. This study reports our experience, compared to the data in the literature, based on 58 insertions of inflatable prosthesis between October 1987 and October 1991. After rigorous patient selection and a mean follow-up of 30 months, the surgeon evaluated the objective results (mechanical functioning of the prosthesis, complications) and subjective results (sexuality) in 51 patients. 69.4% of patients presented an anomaly of prosthesis function, 10.3% developed an infection of the prosthesis, 34.5% required removal of the prosthesis, 59% declared that they were satisfied sexually and sexual activity was restored in 55%. This study therefore appears to contradict the optimistic data reported in the literature.

Monoclonal antibody BL2-10D1 directed against a tumor-associated antigen of bladder carcinoma was used for monitoring 11 intravesically treated patients. Thirty-three bladder washout specimens were used for standard cytology and immunological staining. Prior to treatment, 9 of 11 cytologic specimens examined with standard cytology were found to be positive. Using BL2-10D1 alone, only 6 were positive but 1 patient negative with standard cytology was positive with the antibody and corresponded to a positive histological control. Thus, before treatment, an increase in positive rate was observed using the combination of the 2 methods from 82 to 91%. At the end of treatment, 9 washout specimens remained positive with standard cytology, whereas 1 case negative in standard cytology was positive in immunocytology. Thus, the positive rate increased from 82 to 91%. One month after the end of treatment, of 11 washout specimens tested, 3 false-negative standard cytologies and 4 false-negative immunocytologies were shown. However, used in combination, the two methods lead to an increase in positive rate from 67 to 89%. In view of these results, BL2-10D1 may be considered as a useful reagent in combination with the standard cytology for the confirmation of the presence of tumor cells before and after immunotherapy.

We report 49 tumors of the upper urinary tract treated between 1980 and 1988. Intravenous pyelography with direct opacification technics gave the diagnosis in 83.7% of patients. Ultrasonography and computed tomography were only reliable for tumors of renal pelvis. Urinary cytology gave good results only in high grade invasive transitional cell carcinoma. Nephro-ureterectomy is always recommended.

Between 1985 and 1988, 10 female patients between the ages of 35 and 76 years, suffering from dysuria after surgical correction of urinary stress incontinence (7 sub-urethral bands, 3 colposuspensions) were observed. The abnormality of the course of the urethra compressed anteriorly against the symphysis pubis, observed on clinical examination and on intravenous pyelography as well as urodynamic investigations allowed this dysuria to be attributed to a cervico-urethral obstruction resulting from over correction during the initial surgical operation. The 10 patients were treated by urethro-cervicolysis (9 out of 10) associated with repeated colposuspension in 3 cases. The overall results were disappointing as although 8 of the 10 patients were improved at 3 month, only 4 out of 9 were still improved at 6 months. These poor results raise the question of the value of combining urethro-cervicolysis with colposuspension and possible VY plasty of the bladder neck.

287 urethral strictures were treated between 1974 and 1984. Two-stage urethroplasty provided 47.6% of good results at 5 years, although there was a possibility of very delayed recurrences. Endoscopic urethrotomy only gave 26% of good results at 5 years, while 30% of good results were obtained after dilatation with Olbert's sound. Endourethral techniques do not compete with two-stage urethroplasty, provided they are performed repeatedly.

Twenty-six patients have been operated by pericavernoplasty with a band of synthetic material. After 1 year, 61.6% had a good result. Venous leaking is certainly a disease of the corpora cavernosa.

The authors report the results of 63 internal urethrotomies for urethral stenosis performed during a four year period. The essential sites were perineal and the most frequent aetiology iatrogenic, particularly after prostatectomy. Overall, the authors obtained 18 satisfactory results, 2 severe complications, 24 failures and 17 patients are too recent to assess or were lost from sight. A second endoscopic urethrotomy gave only very little chance of a definitive recovery. Although the results were not constantly excellent, the series studied by the authors shows that endoscopic internal urethrotomy offers the possibility by a simple technique of obtaining a certain number of durable successes whilst not interfering with the subsequent performance of other types of urethroplasty. Finally, in a certain number of cases endoscopic internal urethrotomy facilitates subsequent dilatations.

The authors report an original technique of glans resection without section of the cavernous bodies. A caverno-cutaneous suture enables a neo-glans to be obtained from the distal, tapering part of the cavernous bodies. This technique is used for small and superficial tumors without lymph nodes and located far enough from the balano-preputial fold.

The method of treating urethral strictures described in this article is inspired from the technique for percutaneous angioplasty, using an inflatable catheter. It provides good immediate results in 80% of cases, regardless of the localization of the stricture and the previous treatment.

The authors report thirty nine cases of primary vesicorenal reflux in adults, involving sixty nine ureters. The series includes two women for every three men, with an onset normally in the twenties (the average age was 28 years and 6 months). In 86.6% of the patients, the disorder was revealed by urinary infections, and the case history extended back over an average of eight years. The urinary infection had a severe impact on the renal parenchyma, so that 54% of the patients presented with bilateral parenchymal lesions. Isotopic cystography appears to provide a more sensitive diagnostic tool than conventional radiological cystography, and the radiation effects are far less pronounced, so that the examination can be repeated more frequently in search of intermittent refluxes in patients with pyelonephritic lesions. The surgical management is by uretero-vesical reimplantation. The authors presently prefer Cohen's technique, which gives 88% good results. On the other hand, after surgical élimination of the urinary infection, the pyelonephritic lesions or renal insufficiency are irreversible, but they remain stable.

Parapyelic cysts present particular characteristics in relation to cystic disease of the kidney. Their intrasinusal development in contact with vascular and canalar elements of the renal hilum explains their often explosive symptomatology and the frequent need for surgical excision of the cyst--procedure difficult to accomplish and nearly always incomplete. Four cases are reported, including 2 with cysts communicating with excretory pathways, and symptoms, signs and diagnostic and therapeutic aspects discussed. Arguments are in favor of an acquired pathogenicity of these cysts (communication with excretory pathways, contingent presence of smooth muscle fibres in the cyst wall).

Renal angioplasty was performed in twenty hypertensive patients, and good immediate results were obtained in 18 cases. One unsuccessful result was due to insufficient dilatation of a stenosed renal artery, and another from an accident during dissection of the aortic wall in contact with the renal ostium. Repeated dilatation was necessary in two cases following recurrence of stenosis. A high percentage improvement in the hypertension was obtained: 12 cases recovered and there was marked improvement in 4 other patients, treatment being effective, therefore, in 16 of the 20 patients operated upon. The published literature is reviewed, and emphasis placed on the need for treatment by surgeons experienced in angiography examinations, in close collaboration with the medical and surgical team, the later being ready to intervene if the slightest complication of a surgical nature develops.

This is a comparative study in 183 patients of the treatment of urethral stenoses by two-stage urethroplasty, internal endoscopic urethrotomy and urethrotomy via the Olbert catheter. Urethroplasty (39 patients) was preferentially carried out in patients with moniliform stenosis greater than 2 cm long in the penile and penoscrotal urethra. There was no significant difference in the indications for the two forms of urethrotomy. Good results were obtained for the 3 techniques in about 80% of cases but there was significantly higher complication rate with surgical urethroplasty. The failure rate of the 3 techniques did not differ significantly. The cost of treatment, on the other hand, greatly differed depending on the technique. Surgical urethroplasty was 2.8 times more costly than internal endoscopic urethrotomy and 10.4 times more costly than Olbert catheter urethrotomy. Olbert catheter urethrothomy was 3.7 times cheaper than internal endoscopic urethrotomy.

The treatment of urethral strictures has considerably developed over recent years: surgical urethroplasty has been perfected at the same time as internal urethrotomy has gained a new lease of life as a result of endoscopy. Urethral dilatation by means of probes used for arterial stenoses constitutes another interesting development in this field. We reviewed our case files with a double objective in mind: to determine the reasons for our changing therapeutic practices and the results of these three methods. Our study was also interesting because it was the first time that the incidence of this therapeutic development on the economic consequences of this disease, which generally affects professionally active adults, has been assessed. Several factors can be taken into consideration: however, as the length of time off work and the cost of concomitant drug treatments were unable to be determined with sufficient accuracy by our survey, we finally assessed the duration and the number of hospital admissions for each patient. Although only fragmentary, these data appear to reflect fairly accurately the economic impact of the treatments used.

A new treatment of impotence by venous leakage is reported. It consists of tying the dorsal and lateral aspects of the cavernous body with a bandage of synthetic material. The bandage, inserted on the bulbo-cavernous muscles, restores a "carter effect" and prevents venous leakage during erection. This technique has been used in 20 patients, with satisfactory results in 10 who were followed up for more than 4 months.

An inflatable balloon catheter of the Gruntzig type was used to dilate the urethra of 25 patients. The procedure involves atraumatic catheterization by a vascular catheter under televised urethroscopy, followed by introduction on a flexible guide of the balloon catheter which is then inflated. The stenosis is visible on the balloon and the rapidity with which it "yields" can readily be appreciated. Control of dilatation is effected by voiding urethrography. This method entails much less discomfort than conventional urethral dilatation. No complication was observed in this series. Stenosis recurred in 3 patients who subsequently underwent a second balloon dilatation.

Case-reports of 85 patients with upper urinary tract tumors were reviewed. Mainly affected were males (87% of cases), particularly over 60 years of age, the principal presenting sign being hematuria. Other signs such as renal colic, lumbago or infections were observed more rarely. The renal pelvis was affected in 52 of the 85 patients (two of these were bilateral), multiple tumor foci being present in only 6 cases. Most tumors were epitheliomas (62 papillary and 13 non-papillary), with 52 of these at the superficial stage (0 or A), 21 at stage B 1 and 5 at stage B II or C. Based on Broders' classification, 48 were grade II and 16 grade III tumors. Prognosis was routinely poor in 5 patients with a stage B or C tumor and lymph node extension. Diagnosis is by intravenous urography, although retrograde ureteropyelography has its place, with increasing interest being given to ultrasound and computed tomography examinations combined with routine cystoscopy. If no particular contraindications exist, the preferred treatment is a total one-stage nephro-ureterectomy without curettage (52 cases), although curettage was performed at the same time in 9 other patients. Conservative surgery has only a limited application: 6 patients had segmental resections of the ureter and 2 patients underwent tumorectomy. Postoperative mortality was particularly loco: 4 patients (4,7%), mainly from vascular or respiratory diseases. (4,7%), mainly from vascular or respiratory diseases. Bone (5 cases), pulmonary (3 cases) and medullary (1 case) metastases represented the main cause of death during the year following surgery, all these patients having infiltrating tumors.(ABSTRACT TRUNCATED AT 250 WORDS)