bluuebunny/crossref_metadata_2025 huggingface dataset:
The Correlation between Pre-operative Leukocyte Levels and Length of Stay in Appendicitis Patients after an Appendectomy at Dr. Zainoel Abidin Hospital 2019–2020
Authors: Yusuf Muhammad , Kulsum Kulsum , Gianty Jauza Aqilla
Published: November 2022

BACKGROUND: Appendicitis is an inflammation of the vermiform appendix. The infectious process and the inflammatory response are associated with increased leukocyte levels. Leukocyte levels can be used as the predictor of severity, treatment selection, and outcome of appendicitis patients that affect the length of hospitalization.

AIM: The aims of the study are to determine the correlation between pre-operative leukocyte levels and the length of stay in appendicitis patients after an appendectomy at Dr. Zainoel Abidin Hospital 2019–2020.

METHODS: The study was an observational analytic study with a cross-sectional design. The sampling technique used is total sampling. The data collected were sourced from medical records and obtained from 47 research subjects.

RESULTS: The results showed that both appendicitis patients with leukopenia (<5000 cells/mm3) and normal (5000–10,000 cells/mm3) consist of two subjects which required a short length of hospitalization (<5 days). In the patient with leukocytosis Grade I (≤18,000 cells/mm3), 23 subjects (92%) required a short length of hospitalization and 2 subjects (8%) required a long hospitalization (≥5 days). Meanwhile, patients with leukocytosis Grade II (>18,000 cells/mm3), 8 subjects (40%) required a short length of hospitalization, and 12 subjects (60%) required a long hospitalization . Based on the bivariate analysis using the Chi-square method, obtained p = 0.002 (p < 0.05).

CONCLUSION: There was a correlation between preoperative leukocyte levels and the length of stay in appendicitis patients after an appendectomy at dr. Zainoel Abidin Hospital.
The Clinical Manifestations and Outcomes in Neonates Infected with COVID-19 in the West of Iran
Authors: Eghbalian Fatemeh , Jenabi Ensiyeh , Bashirian Saeid , Khazaei Salman , Shokouhi Maryam , Basiri Behnaz , Sabzehei Mohammad K , Sheikhahmadi Shobo , Babaei Homa , Vakiliamini Mazyar , Jafari Nahid , Jafari Maryam
Published: November 2022

Introduction:

So far, no study has been conducted in Iran on the effect of COVID-19 on neonates. Therefore, the present cross-sectional study has been evaluated to determine the clinical manifestations and outcomes in neonates infected with COVID-19 in the west of Iran.

Materials and Methods:

The present cross-sectional study was conducted among neonates infected with COVID-19 in six provinces of Hamadan, Kermanshah, Kurdistan, Ilam, Zanjan and Lorestan, located in the west of Iran, from 1 March to 1 July 2020. In these neonates, the polymerase chain reaction test was positive. The data were collected by a checklist and were analysed using SPSS Statistics Software.

Result:

During the study period, 16 neonates infected with COVID-19 were identified including Kurdistan Province with five cases, Hamadan Province four cases, Kermanshah with three cases, and Lorestan and Zanjan provinces with two cases. Neonate gender of them had equal distribution. Two (15.38%) of them needed CPR after delivery. The delivery method for 9 (56.25%) was vaginal, and one of them died during the study period. The medical care used for these neonates was as follows: 87.5% were hospitalized in the intensive care unit and antibiotics were used for 68.75%. 12.5% underwent COVID-19-specific treatment, and for 25%, a ventilator was used. The laboratory findings in neonates infected with COVID-19 showed that in 18.75%, blood urea nitrogen has increased. 46.15% of neonates reported lymphocytopenia. The blood haematocrit and haemoglobin decreased by 31.35% and 56.25%, respectively.

Conclusion:

The coronavirus disease 2019 has occurred among neonates, but they seemed to have a milder disease course and better prognosis than adults. Findings showed that there is a possibility of vertical intrauterine transmission from pregnant mothers to newborns.
The Therapeutic Role of Exercise Training in Heart Failure Patients: A Narrative Review
Authors: Laina Ageliki , Soulaidopoulos Stergios , Doundoulakis Ioannis , Arsenos Petros , Kordalis Athanasios , Xydis Panagiotis , Xintarakou Anastasia , Kalantzis Charalampos , Chrysohoou Christina , Dilaveris Polychronis , Archontakis Stefanos , Sotiropoulos Helias , Sideris Skevos , Gatzouli Lila Sklavi , Tsioufis Konstantinos , Gatzoulis Konstantinos Athanasios
Published: November 2022

Cardiac rehabilitation (CR) is a complex intervention that improves functional capacity and quality of life in patients with heart failure (HF). Besides exercise training (ET), CR includes aggressive risk factor management, education about medication adherence, stress management, and psychological support. Current guidelines strongly recommend CR as an integral part of chronic and stable HF patient care. However, CR programs are underused for multiple reasons, namely, low physician referral and patient adherence, high cost, and lack of awareness. In this review, we present existing evidence of the beneficial effects of ET and CR in HF with reduced and preserved ejection fraction, the underlying pathophysiologic mechanisms by which exercise might alleviate symptoms, and the different types of exercise that can be used in HF. Current guidelines supporting the use of CR, reasons for its underutilization, and home-based CR as an alternative or adjunct to traditional center-based programs are also described.
Acanthamoeba keratitis
Authors: Ahmed Nishat Hussain , Rathod Prachala G. , Satpathy Gita , Tandon Radhika , Sharma Namrata , Titiyal Jeewan S.
Published: November 2022

The free-living amebae of genus Acanthamoeba are an important cause of microbial keratitis. The clinical appearance of Acanthamoeba keratitis (AK) usually mimics viral or fungal keratitis. Thus, microbiological workup plays a significant role in the diagnosis and timely treatment of such cases. We report a retrospective case series of seven culture-confirmed AK cases from a tertiary eye care center in North India. Various risk factors and triggers of infection, clinical presentations, microbiological findings, and management of AK are elucidated.
Cyclosporiasis in immunocompetent and immunocompromised patients – A Twelve years experience from a tertiary care centre in Northern India
Authors: Ghoshal Ujjala , Siddiqui Tasneem , Tejan Nidhi , Verma Sheetal , Pandey Ankita , Ghoshal Uday C
Published: November 2022

Context:

Cyclosporiasis is an emerging enteric coccidian parasitic disease worldwide, caused by the parasite Cyclospora cayetanensis. There is scanty data from India, especially among immunocompetent patients.

Aims:

The aim is to evaluate the occurrence of Cyclosporiasis in immunocompetent and immunocompromised patients.

Settings and Design:

It is a prospective cohort study conducted from June 2006 to May 2018 at our tertiary care center.

Materials and Methods:

Stool samples were collected from the 900 patients with diarrhea (both immunocompetent and immunocompromised) and 170 healthy controls to look for Cyclospora by modified Kinyoun staining.

Statistical Analysis:

Mann–Whitney U test/Fisher exact test were used for statistical analysis.

Results:

Oocysts of C. cayetanensis were detected in 10/900 patients and none of the healthy controls. The median age of patients was 38.5 years (10-65 years) and males (6/10) outnumbered the females in harboring the parasite. Eight patients were immunocompromised (five postrenal transplant cases and one-one patient each with HIV, non-Hodgkin's lymphoma, and juvenile polyarthritis), and two patients were immunocompetent. Cyclospora infection was more common in immunocompromised patients (8/300, 2.67%) than the immunocompetent patients (2/600, 0.33%); P < 0.001. Eight patients responded well to trimethoprim-sulfamethoxazole, one died, and one was lost to follow-up. Coinfection with Cryptosporidium spp. was seen in one patient.

Conclusion:

Cyclospora causes diarrhea in both immunocompromised and immunocompetent persons. Its burden may be underestimated due to a lack of awareness and appropriate diagnostic methods. Special staining techniques are important for diagnosis as they may be missed by routine microscopy.
Host-parasite interactions in infections due to Entamoeba histolytica
Authors: Singh Aradhana , Banerjee Tuhina
Published: November 2022

Entamoeba histolytica (E. histolytica) is an enteric microaerophilic protozoan parasite responsible for millions of cases worldwide. Majority of the infections due to E. histolytica remain asymptomatic; however, it can cause an array of symptoms ranging from devastating dysentery, colitis, and abscesses in different vital organs. The interactions between the E. histolytica and its host are a multifaceted chain of events rather than merely destruction and invasion. There are manifold decisive steps for the establishment of infections by E. histolytica which includes degradation of mucosal layer, adherence to the host epithelium, invasion into the host tissues, and dissemination to vital organs. It is widely hypothesized that, for establishment of infections, the interactions at the intestinal mucosa decides the fate of the disease. The delicate communications between the parasite, the host factors, and the associated bacterial microflora play a significant role in the pathogenesis of E. histolytica. In this review, we summarize the interactions between the E. histolytica and it's host at the genetic and immunological interphases emphasizing the crucial role of microbiota in these interactions.
Evaluation of microscopy and PCR for detection of Dientamoeba fragilis
Authors: Tolba Mona Mohamed , Allam Amal Farahat , Khalil Safia Saleh , Elshouki Wagdy Makram , Shehab Amel Youssef
Published: November 2022

Introduction:

Dientamoeba fragilis (D. fragilis) diagnosis is an intestinal protozoan parasite globally found in rural and urban areas and is attracting a growing interest. Its prevalence in stool varies from 0.2% to more than 19% depending upon the population studied.

Materials and Methods:

This study was based on the examination of 100 stool samples of randomly referred cases in a rural area in Motobus district, Kafr El-Sheikh governorate, Egypt. Our aim was to investigate the presence of D. fragilis in stool of the examined individuals using conventional polymerase chain reaction (PCR) compared to wet mount and trichrome stain with confirmation of infection by transmission electron microscopy.

Results:

D. fragilis was detected in 13/100 of the stool samples examined using wet mount smears, while trichrome stain detected 17/100. Conventional PCR diagnosed 41 cases of D. fragilis in the studied group. A very good agreement was found between wet mount and trichrome stain for diagnosing D. fragilis, while there was fair agreement between conventional PCR and both microscopy methods. Transmission electron microscope was performed on pooled positive samples that revealed the internal structures of D. fragilis trophozoite with its characteristic nucleus.

Conclusions:

PCR technique was superior to microscopy for the detection of D. fragilis. Trichrome stain remains vital for microscopic diagnosis.
Transport mechanisms of hydrothermal convection in faulted tight sandstones
Authors: Yan Guoqiang , Busch Benjamin , Egert Robert , Esmaeilpour Morteza , Stricker Kai , Kohl Thomas
Published: November 2022

Abstract. Motivated by the unknown reasons for a kilometer-scale high-temperature overprint of 270 ~ 300 °C in a reservoir outcrop analog (Piesberg Quarry, northwest Germany), numerical simulations are conducted to identify the transport mechanisms of the fault-related hydrothermal convection system. The system mainly consists of a main fault and a sandstone reservoir in which transfer faults are embedded. The results show that the buoyancy-driven convection in the main fault is the basic requirement for elevated temperatures in the reservoir. We studied the effects of permeability variations and lateral regional flow on the preferential fluid flow pathways, dominant heat transfer types, and mutual interactions among different convective and advective flow modes. The sensitivity analysis of permeability variations indicates that lateral convection in the sandstone and advection in the transfer faults can efficiently transport fluid and heat, thus causing elevated temperatures (≥ 269 °C) in the reservoir compared to purely conduction-dominated heat transfer (≤ 250 °C). Higher-level lateral regional flow interacts with convection and advection and changes the dominant heat transfer from conduction to advection in the transfer faults for the low permeability cases of sandstone and main fault. Simulations with anisotropic permeabilities detailed the dependence of the onset of convection and advection in the reservoir on the directional permeability distribution. The depth-dependent permeabilities of the main fault reduce the amount of energy transferred by buoyancy-driven convection. The increased heat and fluid flows resulting from the anisotropic main fault permeability provide the most realistic explanation for the thermal anomalies in the reservoir. Our numerical models can facilitate exploration and exploitation workflows to develop positive thermal anomalies zones as geothermal reservoirs. These preliminary results will stimulate further petroleum and geothermal studies of fully coupled thermo-hydro-mechanical-chemical processes in faulted tight sandstones.
Islamic music listening, spiritual well-being and burnout of employees in Islamic university
Authors: Mohamad Shariff Nurasikin , Azhar Nor Atiqah , Abu Bakar Siti Nurbayani , Ahmad Azmir , Kaderi Mohd Arifin , Saidi Sanisah
Published: November 2022

In Malaysia, working in a university with Islamic vibes that boost spiritual well-being and reduce burnout needs to be supported with empirical evidence. The aim of the study is to examine the relationship between listening to Islamic music, spiritual well-being, and burnout among employees of public universities. A cross-sectional study using an online survey was conducted among 140 employees in a public university during the Covid-19 movement control order in Malaysia (April to May 2021). The set of questionnaires includes socio-demographic data, the types and frequency of music listened by the employees, Modified Maslach Inventory Burnout (MBI), the Duke University Religion Index (DUREL) and spiritual well-being (SWB). The data was analysed using SPSS version 26.0, and hypotheses were tested using the Mann-Whitney U test, Kruskal Wallis and Spearman correlation. The majority of employees listened to music every day, and 51.4% of study participants listened to Islamic music or audio. The study participants have a high level of religiosity (DUREL Mean = 24.02, SD=±2.352), high spiritual well-being (SWB) (Mean= 109.84, SD=±9.014). For the burnout category, there was a low level of depersonalization (Mean= 8.54, SD=±5.728), moderate emotional exhaustion (Mean=20.51, SD=±9.866), and high personal accomplishment (Mean=31.87, SD=±7.956) among employees. SWB correlates positively with personal accomplishment and negatively with emotional exhaustion and depersonalisation (p<.05). The present study highlights that listening to Islamic music has the potential to support the mental well-being and productivity of employees.
Sonographic appearance of uterine scar dehiscence
Authors: Bromley B. , Pitcher B.L. , Klapholz H. , Lichter E. , Benacerraf B.R.
Published: July 2002

We describe the sonographic appearance of two cases of uterine scar separation in patients with prior cesarean deliveries. In the first case, the anteriorly located placenta appeared to be a placenta previa with accreta and in the second case the placenta was also located directly beneath the uterine scar thus masking a separation until the third stage of labor was complete. These two cases demonstrate an unusual sonographic and clinical presentation of uterine scar separation involving anteriorly located placentas.
The amyloid β peptide Aβ (25–35) induces apoptosis independent of p53
Authors: Blasko I. , Wagner M. , Whitaker N. , Grubeck-Loebenstein B. , Jansen-Dürr P.
Published: July 2002

Apoptosis of neuronal cells apparently plays a role in Alzheimer's disease (AD). The amyloid beta (Aβ) peptide derived from β‐amyloid precursor protein is found in AD brain in vivo and can induce apoptosis in vitro. While p53 accumulates in cells of AD brain, it is not known if p53 plays an active role in Aβ‐induced apoptosis. We show here that inactivation of p53 in two experimental cell lines, either by expression of the papillomavirus E6 protein or by a shift to restrictive temperature, does not affect apoptosis induction by Aβ (25–35), indicating that Aβ induces apoptosis in a p53‐independent manner.
PspE (phage‐shock protein E) of Escherichia coli is a rhodanese
Authors: Adams Hendrik , Teertstra Wieke , Koster Margot , Tommassen Jan
Published: July 2002

The psp (hage‐hock rotein) operon of Escherichia coli is induced when the bacteria are infected by filamentous phage and under several other stress conditions. The physiological role of the individual Psp proteins is still not known. We demonstrate here that the last gene of the operon, pspE, encodes a thiosulfate:cyanide sulfurtransferase (EC 2.8.1.1; rhodanese). Kinetic analysis revealed that catalysis occurs via a double displacement mechanism as described for other rhodaneses. The K
ms for SSO3
2− and CN− were 4.6 and 27 mM, respectively.
Deamidation of a model hexapeptide in poly(vinyl alcohol) hydrogels and xerogels
Authors: Lai M.C. , Schowen R.L. , Borchardt R.T. , Topp E.M.
Published: July 2002

Abstract: Polymeric controlled release systems have been proposed to prolong the half‐lives of protein and peptide drugs in vivo and to deliver active drug at a controlled rate. These systems are ineffective, however, if the drug is not stable during storage and release. This study addresses the effect of poly(vinyl alcohol) on the stability and release of an incorporated hexapeptide, VYPNGA, which undergoes deamidation. Two types of peptide‐loaded poly(vinyl alcohol) matrices were formed, a semisolid hydrogel and a lower water content ‘xerogel’, and stored at 50°C for up to 122 days. The hexapeptide was less stable in both poly(vinyl alcohol) matrices than in aqueous buffer or lyophilized polymer‐free powders. The type of poly(vinyl alcohol) matrix appeared to influence the degradation mechanism, since the product distributions differ in the hydrogel and the xerogel. The results suggest that, rather than stabilizing this peptide, incorporation in poly(vinyl alcohol) matrices reduces stability relative to solution and lyophilized controls.
Atopy among schoolchildren in northern and southern Sweden in relation to pet ownership and early life events
Authors: Bråbäck L. , Kjellman N. ‐I. M. , Sandin A. , Björkstén B.
Published: July 2002

Studies have suggested a higher prevalence of asthma and allergies in northern, as compared to southern, Scandinavia. The aim of this study was to evaluate regional differences in atopy in relation to pet ownership and certain early life events among schoolchildren (n = 2108) aged 10–11 years from Linköping in southern Sweden and Östersund in northern Sweden. The parents completed a questionnaire, comprising questions on home environment, heredity, socio‐economic conditions, and the core questions on symptoms from the International Study of Asthma and Allergies in Childhood. The children were skin‐prick tested to eight common inhalant allergens. Information on maternal smoking habits, gestational age, and anthropometric measures were obtained from the Swedish Medical Birth Registry. The prevalence of atopic symptoms and sensitization to pollen were similar in Östersund and in Linköping. A higher prevalence of sensitization to animal dander among children in Östersund could be linked to a higher occurrence of pets in the community. Current cat ownership was related to less sensitivity to cat allergen but only in children with an atopic heredity. Ponderal index > 30 kg/m3 was related to an increased risk of atopic sensitization, both in Linköping (adjusted odds ratio 2.1; 95% confidence interval 1.1–4.0) and in Östersund (adjusted odds ratio 2.0; 95% confidence interval 1.1–3.5). Maternal smoking during pregnancy was related to an increased risk of atopic sensitization among children in Linköping, whereas current smoking was associated with a decreased risk of sensitization in Östersund. In conclusion, we demonstrated that a high occurrence of pets in the community was associated with sensitization, whereas atopic symptoms were essentially unaffected. This study has also suggested an association between body size at birth and atopic sensitization at 10–11 years of age.
Involvement of putative chemical wound signals in the induction of phenolic metabolism in wounded lettuce
Authors: Campos‐Vargas Reinaldo , Saltveit Mikal E.
Published: July 2002

Cutting leaves of Romaine lettuce (Lactuca sativa L. cv. Longifolia) produces a wound signal that induces the synthesis of phenylalanine ammonia lyase (PAL, EC 4.3.1.5) and the accumulation of phenolic compounds in cells up to 2 cm from the site of injury, and tissue browning near the site of injury. The response of leaves within a head of Romaine lettuce to putative chemical wound signals [abscisic acid (ABA), jasmonate (JA) and methyl jasmonate (MeJA)] differed significantly with leaf age. Exposure of harvested heads of lettuce to ABA, JA, MeJA, or salicylic acid (SA) did not induce changes in PAL activity, the concentration of phenolic compounds or browning in mature leaf tissue that was similar to the level induced by wounding. Methyl jasmonate applied as vapour (10, 100 or 1000 µl kg−1 FW), or as an aqueous spray or dip (0.01–100 µM) at 5 or 10°C did not produce an effect on PAL activity or browning that differed significantly from the untreated controls. In contrast, JA, MeJA and SA did induce elevated levels of PAL activity in younger leaves. However, the levels induced were far lower than those induced by wounding. Wound induced phenolic metabolism in mature leaves appears to be induced by different signals than those functioning in young leaves.
Low‐dose (1 μg) adrenocorticotrophin (ACTH) stimulation as a screening test for impaired hypothalamo–pituitary–adrenal axis function: sensitivity, specificity and accuracy in comparison with the high‐dose (250 μg) test
Authors: Tordjman Karen , Jaffe Anat , Trostanetsky Yana , Greenman Yona , Limor Rona , Stern Naftali
Published: July 2002

OBJECTIVE

We have shown previously that in contrast to the standard high‐dose 250‐μg ACTH test, a low‐dose 1‐μg ACTH stimulation test correctly identified all patients with pituitary disease who had impaired hypothalamo–pituitary–adrenal (HPA) function. In this study we further compared the performances of these two tests as screening procedures for possible HPA impairment.

DESIGN

A comparison of the 1‐μg and the 250‐μg ACTH stimulation tests in healthy controls and in patients with pituitary disease whose HPA axis status was characterized formally by a gold standard test.

SUBJECTS

A total of 89 subjects were investigated: 27 healthy normal controls, 43 patients with pituitary disease and normal HPA function, and 19 patients with various pituitary diseases and impaired HPA function.

MEASURES

All 89 subjects underwent stimulation with 1 μg ACTH; 80 also underwent the high‐dose 250‐μg ACTH test. A receiver operating characteristic analysis (ROC) was performed to compare the tests.

RESULTS

Using a stimulated cortisol > 500 nmol/l as the criterion for a normal response, the 1‐μg ACTH stimulation identified 18 of the 19 subjects with impaired HPA function (94.7% sensitivity with a likelihood ratio of 0.0588 for a negative test). In contrast, 15/16 passed the high‐dose test (a 6.2% sensitivity with a likelihood ratio of 0.875 for a negative test). All normal controls, and 36/43 patients with preserved HPA function, passed the 1‐μg ACTH test (90% specificity). This degree of accuracy was unrivalled by the high dose test at all the cut‐off levels considered.

CONCLUSIONS

More sensitive and accurate, the low‐dose 1‐μg ACTH test is as simple and safe as the standard 250‐μg test. We suggest it should replace it in screening for adrenal insufficiency.
Unionid growth patterns in rivers of differing riparian vegetation
Authors: Morris Todd J. , Corkum Lynda D.
Published: July 2002

1. Growth rates were examined as potential controlling agents of unionid distributions.

2. Analyses of long‐term growth in unionid shells revealed two distinct patterns. Species which dominate rivers with forested riparian vegetation (e.g. Elliptio dilatata) show slow growth throughout life, whereas species which dominate grassy rivers (e.g. Pyganodon grandis) show rapid growth during early life and achieve a smaller maximum size at a younger age.

3. Pyganodon grandis, which occurs in both river types but is much more abundant in grassy habitats, demonstrates a single growth pattern in both basin types. In contrast, Lasmigona complanata (Barnes, 1823), which occurs equally in both basin types, demonstrates two growth patterns which differ depending upon which river is inhabited. In forested rivers, L. complanata grow slow and steady, whereas in grassy rivers, these unionids grow faster and achieve maximum size earlier.

4. Short‐term transplant studies of P. grandis and E. dilatata confirmed this pattern of growth for specialist species.
Adapting a patch model to simulate the sensitivity of Central‐Canadian boreal ecosystems to climate variability
Authors: Price D. T. , Halliwell D. H. , Apps M. J. , Peng C. H.
Published: July 2002

AimTo investigate effects of within‐season and interannual climate variability on the behaviour of boreal forest ecosystems as simulated by the FORSKA2 patch model.

LocationEleven climate station locations distributed along a transect across the boreal zone of central Canada.

MethodsFORSKA2′s water balance submodel was modified to enable it to behave more realistically under a varying climate. Long‐term actual monthly time‐series of temperature and precipitation data were detrended and used to drive the modified model. Long‐term monthly averages of the same detrended data were used to drive the unmodified model.

ResultsModifications created significant improvements when simulating species composition at sites in boreal Canada. Simulated forest biomass values were slightly higher than those obtained from the unmodified model using averaged climate records, but resembled the observed distribution of vegetation more closely.

Main conclusionsModified FORSKA2 suggests that boreal forest composition and distribution may be more sensitive to changes in monthly rainfall data than to changes in temperature. Climate variability affects seasonal water balances and should be considered when using patch models to forecast vegetation dynamics during and following a period of climate transition. The modified model provided improved representation of the latitudinal trend in spatially averaged biomass density in this region.
Comparison of long versus short duration of anticoagulant therapy after a first episode of venous thromboembolism: a meta‐analysis of randomized, controlled trials
Authors: Pinede L. , Duhaut P. , Cucherat M. , Ninet J. , Pasquier J. , Boissel J. P.
Published: July 2002

Abstract. Pinede L, Duhaut P, Cucherat M, Ninet J, Pasquier J, Boissel JP (Hôpital Edouard Herriot and Unité de Pharmacologie Clinique, Lyon, France). J Intern Med 2000; 247: 553–562.

Objective. To assess the length of oral anticoagulant therapy (short versus long duration) after a first episode of venous thromboembolism (VTE).

Design. Meta‐analysis of randomized controlled trials, comparing two durations of anticoagulation, identified in 1999 by a computerized search of the Cochrane Controlled Trial Register, Medline and Embase, completed by an extensive review of the references of pertinent articles.

Setting and subjects. The meta‐analysis was performed on literature data. Seven published controlled trials were included. Relative risks with 95% confidence intervals were computed using the relative risk logarithm method. Statistical significance was set up at 0.01 for the test of association.

Main outcome measures. Outcomes are major haemorrhage and recurrence after a 12‐month follow‐up.

Results. For the recurrence end‐point (sample size of 2304 patients), a duration treatment of 12–24 weeks seems preferable to a 3–6 week regimen, with a relative risk (RR) of 0.60 (95% CI: 0.45–0.79, P < 0.001). For the major haemorrhage end‐point (1823 patients), the RR is not significantly different from 1 (RR = 1.43, 95% CI: 0.51–4.01, P = 0.5). The results were similar for the subgroup ‘permanent risk factors’ or ‘idiopathic VTE’ (RR for recurrence = 0.48, 95% CI: 0.34–0.68, P < 0.001). The tendency was similar, although not reaching statistical significance, for the ‘temporary risk factors’ subgroup (RR for recurrence = 0.34, 95% CI: 0.13–0.93, P = 0.035).

Conclusions. After a first episode of VTE, a long‐term treatment regimen allows a significant reduction in the incidence of recurrences without increasing the incidence of bleeding events.
Graphical trees: the simultaneous display of risk of fetal death by pregnancy history and maternal age
Authors: Whitley
Published: July 2002

Many epidemiological studies consider sequences of events over time where the outcome of interest is determined, at least in part, by similar outcomes that have occurred in the past, e.g. risk of fetal death in successive pregnancies. In this situation, a probability tree can provide useful insights into the relationship between successive events. However, probability trees are usually limited to the display of a single variable, whereas the majority of studies also include other risk factors. Analyses involving other factors, particularly those that consider interactions, can produce an abundance of results that make identification of potentially interesting patterns difficult. A new graphical approach is described for simultaneously presenting the effects of two risk factors where one relates to a sequence of events over time. The graphical tree highlights patterns in the raw data and is therefore proposed for use in exploratory analyses and hypothesis generation. The approach is introduced and illustrated in the context of risk factors for fetal death, and an interaction between pregnancy history and maternal age is explored.
Pre‐operative chemo‐radiotherapy in locally advanced rectal cancer: Is this the way of future management?
Authors: Elsaleh H , Joseph D , Levitt M , Dewar J , Hazel G Van , Einhorn S , Cameron F , Osborne M , Latham M , Robbins P
Published: July 2002

The purpose of the present paper was to update a prospective analysis (H Elsaleh et al. unpubl. data, 1997) investigating the effectiveness and toxicity of pre‐operative pelvic radiotherapy with modest dose 5‐fluorouracil (5‐FU) in locally advanced rectal cancer (T3–T4). A total of 31 patients were assessed (28 T3 and three T4 tumours). Pre‐operative pelvic radiotherapy was delivered in four fields, 45 Gy to the International Commission on Radiation Units and Measurements (ICRU) point in 25 fractions over 5 weeks. A radiosensitizing dose of 5‐FU was delivered at 500 mg/m2 on days 1, 2 and 3, and days 22, 23 and 24. Mesorectal excision of the rectal tumour either by anterior or abdomino‐perineal resection was planned at 4–6 weeks from completion of pre‐operative treatment. Response to therapy was assessed by fresh macroscopic measurement of the surgical specimen. Patients had a low toxicity profile; an estimated 50% or greater response was seen in 24 out of 31 (two complete responses). There were no surgical difficulties achieving resection. No late complications were documented, although follow‐up was short. In locally advanced rectal cancer, pre‐operative chemo‐radiotherapy had a low toxicity profile. Appropriately fractionated pre‐operative chemo‐radiotherapy is a reasonable option in this disease and should be further evaluated. The optimal method of delivery of the radiosensitizing agent (5‐FU) is the subject of further investigation.
Renal duplication anomalies in the fetus: clues for prenatal diagnosis
Authors: Abuhamad A. Z. , Horton C. E. , Horton S. H. , Evans A. T.
Published: July 2002

Duplex kidneys are one of the most common major congenital abnormalities of the urinary tract. The antenatal diagnosis of duplex kidney and its associated ureterocele is infrequent. We report on our experience with the prenatal diagnosis of duplex kidneys in seven fetuses over the past 24 months. In all fetuses, the sagittal length of the duplex kidney was above the 95th centile for gestational age. A ‘cyst‐like’ structure in the upper pole of the duplex kidney and a ureterocele in the urinary bladder were present in all of the seven fetuses. An ipsilateral dilated ureter was seen in six of seven fetuses. Postnatal confirmation of renal duplication anomalies was obtained in all neonates. Increased familiarity of the prenatal sonographer with duplex kidney will allow for its antenatal diagnosis and thus early postnatal treatment. Copyright © 1996 International Society of Ultrasound in Obstetrics and Gynecology
A Comparison of CO2 Uptake by the Green Algae Tetraedron minimum and Chlamydomonas monoica
Authors: van Hunnik E. , van den Ende H. , Timmermans K. R. , Laan P. , de Leeuw J. W.
Published: July 2002

Abstract: The ability of the green alga Tetraedron minimum to acquire inorganic carbon from its environment was investigated and compared with that of Chlamydomonas monoica. T. minimum showed a higher affinity for bicarbonate ions than C. monoica, regardless of whether it was grown at high or low CO2 concentrations. Furthermore, T. minimum was distinguished by the fact that it maintained a large intracellular pool of inorganic carbon. These features may explain why this alga is able to proliferate in alkaline conditions.
Two-dimensional electron system with extremely low disorder
Authors: Shayegan M. , Goldman V. J. , Santos M. , Sajoto T. , Engel L. , Tsui D. C.
Published: July 2002

We report on the growth of modulation-doped GaAs/AlxGa1−x As heterostructures with extremely low disorder by molecular beam epitaxy. In growing these structures we employed the atomic plane doping technique and ultrathick (>1000 Å) spacer layers with graded composition. The structures have mobilities (μ) on the order of 1×106 cm2/V s (at 4.2 K) for areal densities (ns) as low as 4×1010 cm−2. Quantum transport measurements in these structures exhibit new fractional quantum Hall states and demonstrate their exceptionally high quality.
Exchange interactions in quantum well subbands
Authors: Bandara K. M. S. V. , Coon D. D. , O Byungsung , Lin Y. F. , Francombe M. H.
Published: July 2002

It is shown that exchange interactions in the two-dimensional electron gas in quantum wells could cause observable effects on subband energies and intersubband transition energies. In the case of doped quantum wells, the intrasubband exchange interaction can produce an energy shift which is substantially larger than the direct Coulomb energy shift. Theoretical estimates of such shifts are compared with experimental measurements of the infrared photoconductivity of multiple quantum well AlGaAs/GaAs structures with wells doped at about 1018 cm−3.
Electron yield of glow discharge cathode materials under helium ion bombardment
Authors: Szapiro B. , Rocca J. J. , Prabhuram T.
Published: July 2002

The secondary electron emission coefficient of materials for helium ion bombardment in the energy range 0.5–20 keV was measured for the surface conditions of cathodes in high voltage glow discharges. The materials studied are oxidized aluminum, oxidized magnesium, a molybdenum-aluminum oxide sintered composite, molybdenum, stainless steel, copper, gold, and graphite. Each sample was surface conditioned by operating it as cathode of a helium glow discharge shortly before the electron yield measurement. The results are relevant to the modeling of glow discharges and the design of cold cathode electron guns.
Time and temperature dependence of instability mechanisms in amorphous silicon thin-film transistors
Authors: Powell M. J. , van Berkel C. , Hughes J. R.
Published: July 2002

We have measured the time and temperature dependence of the two prominent instability mechanisms in amorphous silicon thin-film transistors, namely, the creation of metastable states in the a-Si:H and the charge trapping in the silicon nitride gate insulator. The state creation process shows a power law time dependence and is thermally activated. The charge trapping process shows a logarithmic time dependence and has a very small temperature dependence. The results for the state creation process are consistent with a model of Si dangling bond formation in the bulk a-Si:H due to weak SiSi bond breaking stabilized by diffusive hydrogen motion. The logarithmic time dependence and weak temperature dependence for the charge trapping in the nitride suggest that the charge injection from the a-Si:H to the nitride is the rate limiting step and not subsequent conduction in the nitride.
Temperature-tunable second-harmonic generation in zinc germanium diphosphide
Authors: Bhar G. C. , Das S. , Chatterjee U. , Vodopyanov K. L.
Published: July 2002

Second-harmonic generation of tunable CO2 laser radiation is reported and analyzed in ZnGeP2 both by angular and temperature tunings. Temperature tuning can thus be advantageously employed in this crystal for nonlinear devices.
Nitrogen-implantation-induced transformation of iron to crystalline Fe16N2 in epitaxial iron films
Authors: Nakajima Kensuke , Okamoto Shoichi
Published: July 2002

Crystalline phase Fe16 N2 has been found in nitrogen-implanted epitaxial iron films on mirror-polished (100) MgO substrates. Implantations of N+2 at an acceleration voltage of 140 keV transformed the bcc iron into a partially ordered nitrogen martensite with a body-centered-tetragonal (bct) structure. The amount of the ordered part was increased to some extent by an annealing treatment in vacuum at 150 °C for 2 hr. An implantation with a dose of 4×1016 N2/cm2 transformed 60% iron in a film into the bct martensite. The constituent of the ordered phase (Fe16 N2 ) in the bct martensite was 16 wt. %. After the annealing, the constituent increased to 24%. It is proposed that a formation of lower temperature and metastable compound such as Fe16 N2 can be made available through energetic ion implantation.
High-speed binary optically addressed spatial light modulator
Authors: Moddel G. , Johnson K. M. , Li W. , Rice R. A. , Pagano-Stauffer L. A. , Handschy M. A.
Published: July 2002

We describe the structure and operating characteristics of a high-speed optically addressed spatial light modulator (OASLM) with a hydrogenated amorphous silicon (a-Si:H) photosensor and a ferroelectric liquid-crystal modulator. The photosensor is a p-i-n photodiode, which switches the liquid crystal into one of two stable states. Under a write-light intensity of 6 mW/cm2, the OASLM exhibits a response time of 155 μs, a contrast ratio of 20:1, and a resolution of 40 lp/mm. The writing sensitivity per pixel is 0.1 pJ.
I
n s
i
t
u laser deposition of Y1Ba2Cu3O7−x high T
c superconducting thin films with SrTiO3 underlayers
Authors: Wiener-Avnear E. , Kerber G. L. , McFall J. E. , Spargo J. W. , Toth A. G.
Published: July 2002

Thin films of Y1Ba2Cu3O7−x (YBCO) with and without underlayers of SrTiO3 (STO) were deposited via pulsed laser deposition onto substrates of sapphire and silicon-on-sapphire (SOS) in a single vacuum step. The YBCO films with STO underlayers displayed better superconducting transitions than the YBCO films without underlayers, with zero-resistance temperatures of 86.5 and 75 K for films with underlayers on sapphire and SOS substrates, respectively. X-ray diffraction and secondary-ion mass spectroscopy have been used to explore the role played by the STO underlayer in improving film quality.
Epitaxial growth of crystalline, diamond-like films on Si (100) by laser ablation of graphite
Authors: Martin J. A. , Vazquez L. , Bernard P. , Comin F. , Ferrer S.
Published: July 2002

Pulsed laser evaporation has been used to deposit ultrathin (<1 nm) carbon films on Si (100) in an ultrahigh vacuum environment. Auger spectroscopy studies revealed a layer-by-layer growth up to the fourth layer. Within this coverage range, the electronic structure of the carbon atoms evolves from carbidic to diamond-like. Above two layers the topmost one consists exclusively of carbon atoms as evidenced by low-energy ion scattering experiments. Scanning tunneling microscopy shows that the films are crystalline and that the surface lattice is hexagonal.
Phase stability and decomposition of superconductive YBa2Cu4O8
Authors: Wada Takahiro , Suzuki Nobuo , Ichinose Ataru , Yaegashi Yuji , Yamauchi H. , Tanaka Shoji
Published: July 2002

The stability of the YBa2Cu4O8 phase has been studied with respect to oxygen partial pressure P(O2 ) and temperature by x-ray diffraction, thermogravimetry, and differential thermal analysis. The critical temperature Td for the decomposition of YBa2Cu4O8 phase was determined from thermal analyses. It was found that Td was strongly dependent on P(O2 ) and the following empirical relation was obtained: log[P(O2)(atm)]=12.41−(1.449×104)/Td(K). It was found that, when heated, YBa2Cu4O8 first decomposed into YBa2 Cu3.5 O7.5−z plus CuO for 0.02 atm<P(O2 )<9 atm, while for P(O2 )≤0.02 atm, it decomposed into YBa2Cu3O7−z plus CuO without yielding YBa2Cu3.5O7.5−z .
Novel all-high T
c epitaxial Josephson junction
Authors: Chin D. K. , Van Duzer T.
Published: July 2002

Josephson junctions are essential components in high-temperature superconductive integrated circuits. YBaCuO/Nb-doped SrTiO3/YBaCuO epitaxial Josephson junctions have been designed, fabricated, and tested. The YBaCuO and Nb-doped SrTiO3 films were deposited by off-axis sputtering. Both dc and ac Josephson effects have been observed and the supercurrent persists up to 80 K. The critical current density is an exponential function of the barrier layer thickness. The product of critical current and normal resistance is between one and three millivolts. A superconducting quantum interference device made of the junctions displays magnetic field modulation of critical current.
Nanosecond time-resolved study of pulsed laser ablation in the monolayer regime
Authors: Herminghaus S. , Leiderer P.
Published: July 2002

Pulsed laser ablation of few angstroms or organic material is investigated on a nanosecond time scale for the first time. The use of optically excited surface plasmons as a probe provides high sensitivity with respect to the thickness of ablated material. The results show that for the films used in our investigation (isopropanol, acetone, and tetrafluoromethane), ablative photodecomposition is not relevant for the ablation process, although there is evidence for chemical transformations.
Effects of high-temperature annealing on amorphous BiFeO3 with nonmagnetic substitutions
Authors: Rao B. Uma Maheshwar , Srinivasan G.
Published: July 2002

We report on the preparation of amorphous (a-) insulators with the highest saturation induction ever achieved. Samples of a-(1 − x)BiFeO3−xABO3 (AB=PbZr, PbTi, BaTi) with x=0–0.6 were prepared by rf sputtering techniques. As-deposited films are x-ray amorphous and are paramagnetic. Films annealed in air at temperatures Ta=400–750 °C develop a magnetic moment. The room-temperature magnetization M increases with Ta and shows a maximum for a specific Ta value which is a function of the nature and amount of the nonmagnetic substitution. With further increase in Ta, the observed decrease in M is accompanied by the onset of crystallization in the films. The largest saturation induction, 4πMs = 3.8 kG, is observed for samples substituted with 0.5 PbZrO3. The Curie temperatures are in the range 380–440 °C and are well below the crystallization temperature.
Continuous amorphous antimony thin films obtained by low-energy cluster beam deposition
Authors: Jensen Pablo , Melinon Patrice , Treilleux Michel , Hoareau Alain , Hu Jian Xiong , Cabaud Bernard
Published: July 2002

We have prepared continuous amorphous antimony thin films by low-energy cluster beam deposition. Contrary to the antimony films prepared by molecular beam deposition, this new technique allows preparation of continuous amorphous films which are stable at room temperature. This study has been carried out by combining electrical measurements and transmission electron microscopy observations.
Rapid solidification of polymorphic transition metals induced by nanosecond laser pulses
Authors: Vitta Satish
Published: July 2002

A Nd-YAG laser giving 5 ns, 266 nm pulses was used to melt and subsequently quench thin, pure metallic films on a liquid Al/Al2O3 substrate at 1010–1012 K s−1. Transmission electron microscopy together with electron diffraction was used to study the competitive nucleation and growth behavior of the crystals from the undercooled melt. In the case of Fe and Co the high-temperature bcc and fcc structures were retained after laser quenching. Ti and Zr in spite of the structural similarities exhibit different preferences for nucleation from the undercooled melt. In all the metals the solid-state transformations were completely suppressed and the crystal growth was found to be limited by the collisional frequency of the atoms onto the growing interface.
Inverted cavity GaAs/InGaAs asymmetric Fabry–Perot reflection modulator
Authors: Hu Kezhong , Chen Li , Madhukar Anupam , Chen Ping , Kyriakakis Chris , Karim Zaheed , Tanguay Armand R.
Published: July 2002

We report the realization of an inverted cavity (through-substrate) reflection modulator based on an asymmetric Fabry–Perot configuration that utilizes the transparency of the GaAs substrate for operation at wavelengths appropriate for strained-layer GaAs/InGaAs multiple quantum wells. At room temperature, a contrast ratio of 12:1 is realized along with a dynamic range of 20% at an operating wavelength of 9565 Å.
Phase-matching retracing behavior: New features in LiB3O5
Authors: Lin Shujie , Wu Baichang , Xie Fali , Chen Chuangtian
Published: July 2002

Retraces of phase-matching (PM) angles and noncritical phase-matching temperatures for both type I and type II second harmonic generation in LiB3O5(LBO) are first demonstrated. By fitting to the measured PM angles at room temperature, new Sellmeier’s equations of LBO are obtained. Further analyzing the spectral and angle acceptances, we point out that LBO is particularly useful in doubling radiations near 1.3 μm such as 1.32 μm of Nd:YAG, 1.31 μm of Nd:YLF, and 1.34 μm of Nd:YAP.
Effect of thermal treatment of passivation integrity of chemical vapor deposition silicon nitride
Authors: Domanský Karel , Petelenz Danuta , Janata Jiří
Published: July 2002

The relationship between the pinhole density in silicon nitride layers deposited on oxide-silicon structures and etching in buffered hydrofluoric acid is investigated in relation to the cooling down rate after Si3N4 deposition and subsequent annealing conditions. Si3N4 layers were deposited using a high temperature atmospheric pressure chemical vapor deposition technique on SiO2 patterned silicon substrates additionally covered with a thin SiO2 layer. Average numbers of pinholes per chip, as function of etch time, are presented both for differently treated wafers and for the specific locations on chips. The phenomenon is attributed to the preferential etching of Si3N4 in locations under stress.
Growth of AlxGa1−xAs parabolic quantum wells by real-time feedback control of composition
Authors: Aspnes D. E. , Quinn W. E. , Tamargo M. C. , Pudensi M. A. A. , Schwarz S. A. , Brasil M. J. S. P. , Nahory R. E. , Gregory S.
Published: July 2002

Epitaxial AlxGa1−xAs structures whose compositions x vary continuously with thickness according to a given input function have been grown by chemical-beam epitaxy under closed-loop ellipsometric control. 200- and 500-Å parabolic quantum wells analyzed by photoreflectance and secondary-ion mass spectrometry, respectively, show that actual compositions follow target values to within 0.02 in x. Growth of the 200-Å profile was controlled using compositions ellipsometrically determined for the outermost running 3.1 Å (∼1 monolayer) of depositing material.