bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radiation polymerization and controlled drug release of polymer hydrogels with NIPA and NVP
Authors: Zhuang Yinfeng , Yang Hua , Wang Guowei , Zhu Zhongqi , Song Weiqiang , Zhao Huidong 
Published: February 2003

AbstractP(NIPA–NVP) and P(NIPA)/PVP interpenetrating polymer network hydrogels were synthesized by radiation polymerization in this article. Acetylsalicylic acid proved a model drug of salt resistance. Drug‐controlled release of these hydrogels containing acetylsalicylic acid was investigated. Influences of radiation dose, feed composition on the lower critical solution temperature (LCST), swelling behavior, salt dissolubility, and controlled release effect were discussed. The preferable preparation conditions for the titled aim were dose rate of 1 KGy/h, total dose of 30 KGy, feed monomer ratio of NIPA:NVP between 1:1 and 4:1, and total monomer concentration of 10%. As NVP content of the hydrogel increased, LCST rose, swelling ratios increased, salt resistance improved, and both swelling and deswelling rates slowed. Due to the ability of forming association complex, these hydrogels had the function of solubilization that made the drug release of difficult dissoluble medicine effective. These hydrogels had a higher drug release at physiological environment. The experimental results showed that these hydrogels were promising materials for causing solubilization and developing a long‐term controlled release system. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 724–729, 2003
Effect of solvent on properties of solution‐cast dense SPPO films
Authors: Kruczek B. , Matsuura T. 
Published: February 2003

AbstractThe effect of solvent on properties of solution‐cast dense films was investigated using high molecular weight sulfonated poly(2,6‐dimethyl‐1,4‐phenylene oxide) (SPPO) and five different solvents having relatively similar molar volumes. The study revealed that polymer–solvent interactions existing in casting solution primarily determine the concentration of residual solvent and surface morphology of the films. On the other hand, the O2 and CO2 permeabilities, which for most permeable films were more than three times greater than for the least permeable ones, appear to be governed by the volatility of solvent in casting solution. At the same time, the more permeable films showed lower O2/N2 and CO2/CH4 permeability ratios than the less permeable ones. In addition to physical factors such as polymer–solvent interactions and volatility of solvent in casting solution, the differences in gas transport properties of SPPO films could arise from the formation of quaternary salts—in particular, in the case of films prepared from the pyridine solution. The analysis of casting solution properties, surface images by atomic force microscopy, and gas transport properties allowed us to associate defective structures of some SPPO films with a specific surface morphology and a particular combination of solvent properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1100–1110, 2003
Structural properties of CrF3‐ and MnCl2‐filled poly(vinyl alcohol) films
Authors: Zidan H. M. 
Published: February 2003

AbstractPoly(vinyl alcohol) (PVA) films filled with different amounts of CrF3 and MnCl2 were prepared by the casting method. Differential scanning calorimetry (DSC) and X‐ray diffraction (XRD) analysis were used to study the changes in the structure properties that occurred because of filling. The changes occurring in the measured parameters with increasing filler contents were interpreted in terms of the structural modification of the PVA matrix. All the studied samples had a main melting temperature due to the main crystalline phase of PVA. The intensity and position of this peak depended on the filling level. However, the samples of CrF3‐filled PVA films with a filling level greater than or equal to 10 wt % revealed another melting temperature, which indicated the presence of a new crystalline phase in addition to the main crystalline phase. The changes that occurred in the degree of crystallinity of the studied samples were examined. The calculated degree of crystallinity was formulated numerically to be an exponential function of the filling level. The XRD patterns of the studied samples confirmed the DSC results. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1115–1120, 2003
Polycondensation of sodium tetrazodiphenyl naphthionate and pyromellitic dianhydride under microwave irradiation and the performance of the third‐order nonlinear optics
Authors: Tang Xiubo , Lu Jianmei , Zhang Zhengbiao , Zhu Xiulin , Wang Lihua , Li Najun , Sun Zhenrong 
Published: February 2003

AbstractSodium tetrazodiphenyl naphthionate and pyromellitic dianhydride were polycondensed under microwave irradiation and oil‐bath heating. The resultant poly(amic acid) was imidized in the solid phase by microwave irradiation and oil‐bath heating. The effects of the reaction temperature, the concentration of monomers, the monomer ratio, and the microwave irradiation time on the conversion, intrinsic viscosity, and third‐order nonlinear optical (NLO) coefficient of the polymer were investigated. The results showed that the polycondensates had high third‐order NLO coefficients (χ(3) = 1.476 × 10−12esu) and very fast time responses (15.79 ps). The χ(3) values of the polycondensates under microwave irradiation were higher than those of conventional thermopolymerization. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1121–1128, 2003
Interaction of crosslinked ethylene–propylene–diene terpolymer blends with chlorinated organic penetrants
Authors: Siddaramaiah  , Roopa S. , Guruprasad K. H. 
Published: February 2003

AbstractThe sorption and diffusion of halogenated hydrocarbon penetrants through different ethylene–propylene–diene terpolymer (EPDM) blends, such as EPDM/natural rubber, EPDM/bromobutyl rubber, and EPDM/styrene butadiene rubber (50/50 w/w), were studied. The diffusion coefficient of halogenated penetrants fell in the range 1.5–14.52 × 10−7 cm2/s in the temperature range of 25–60°C. Transport data were affected by the nature of the interacting solvent molecule rather than its size and also by the structural variations of the EPDM blends. 1,2‐Dichloroethane showed a lower mass uptake compared to other penetrants. The temperature dependence of the transport coefficient was used to estimate the activation parameters, such as the activation energy of diffusion (ED) and the activation energy of permeation (Ep) from Arrhenius plots. The activation parameters for ED of aliphatic chlorinated organic penetrants was in the range 7.27–15.58 kJ/mol. These values fell in the expected range for rubbery polymers, well above their glass‐transition temperature. Also, the thermodynamic parameters, such as enthalpy and entropy, were calculated and fell in the range 2–15 kJ/mol and 3–54 J/mol/K, respectively. Both first‐ and second‐order transport kinetics models were used to investigate the transport kinetics, and first‐order kinetics were followed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1366–1375, 2003
Implementing relevance feedback in the Bayesian Network Retrieval model
Authors: de Campos Luis M. , Fernández‐Luna Juan M. , Huete Juan F. 
Published: February 2003

AbstractRelevance Feedback consists in automatically formulating a new query according to the relevance judgments provided by the user after evaluating a set of retrieved documents. In this article, we introduce several relevance feedback methods for theBayesian Network Retrieval Model.The theoretical frame on which our methods are based uses the concept of partial evidences, which summarize the new pieces of information gathered after evaluating the results obtained by the original query. These partial evidences are inserted into the underlying Bayesian network and a new inference process (probabilities propagation) is run to compute the posterior relevance probabilities of the documents in the collection given the new query. The quality of the proposed methods is tested using a preliminary experimentation with different standard document collections.
Size of the pancreatic head as a prognostic factor for the outcome of Beger's procedure for painful chronic pancreatitis
Authors: Keus E , van Laarhoven C J H M , Eddes E H , Masclee A A M , Schipper M E I , Gooszen H G 
Published: February 2003

Abstract

Background
Duodenum-preserving resection of the head of the pancreas (DPRHP) according to Beger has been developed as an alternative to pylorus-preserving resection of the pancreatic head for painful chronic pancreatitis.

Methods
Between 1988 and 2000, 36 consecutive DPRHPs were performed. The group was divided into patients with (group 1; n = 23) and without (group 2; n = 13) significant enlargement of the pancreatic head. Pain was the indication for surgery in all patients.

Results
Complications occurred in 12 patients, necessitating reoperation in 11. Initial overall results were favourable; significant improvement or complete relief of pain was reported in 27 of 35 patients. Long-term results were obtained in 27 of 30 patients; the overall success rate was 16 of 27, 13 of 16 patients with distinct enlargement of the pancreatic head and 3 of the 11 with minimal or no enlargement (P = 0·018).

Conclusion
DPRHP can be performed with good early results. This effect is sustained in patients with distinct localized disease of the pancreatic head. In those without, the long-term results are disappointing.
Factors predictive of 5-year survival after transarterial chemoembolization for inoperable hepatocellular carcinoma
Authors: O'Suilleabhain C B , Poon R T P , Yong J L , Ooi G C , Tso W K , Fan S T 
Published: February 2003

Abstract

Background
Transarterial chemoembolization (TACE) is widely used for unresectable hepatocellular carcinoma (HCC), but the long-term survival benefit remains unclear.

Methods
Pretreatment variables were analysed for factors predictive of actual 5-year survival from a prospective database of patients with inoperable HCC treated by TACE between 1989 and 1996.

Results
Complete 5-year follow-up (median 91 months) was obtained for 320 patients who underwent a median of 4 (range 1–41) TACEs. Median tumour size was 9 (range 1–28) cm. There were 25 5-year survivors (8 per cent), including eight with tumours larger than 10 cm in diameter and three with portal vein branch involvement. On univariate analysis, female gender (P = 0·037), absence of ascites (P = 0·028), platelet count below 150 ×109 per litre (P = 0·011), albumin concentration greater than 35 g/l (P = 0·04), α-fetoprotein level below 1000 ng/ml (P = 0·007), unilobar tumour (P = 0·027), fewer than three tumours (P = 0·015), absence of venous invasion (P = 0·011), and tumour diameter less than 8 cm (P = 0·021) were significant predictors of 5-year survival. Albumin concentration greater than 35 g/l (P = 0·011), unilobar tumour (P = 0·012) and α-fetoprotein level below 1000 ng/ml (P = 0·014) were independent prognostic factors on multivariate analysis.

Conclusion
Five-year survival is possible with TACE for inoperable HCC, even in some patients with advanced tumours. Unilobar tumours, α-fetoprotein level below 1000 ng/ml and albumin concentration greater than 35 g/l were factors predictive of 5-year survival.
Non-suture methods of vascular anastomosis
Authors: Zeebregts C J , Heijmen R H , van den Dungen J J , van Schilfgaarde R 
Published: February 2003

Abstract

Background
The main aim of performing a vascular anastomosis is to achieve maximal patency rates. An important factor to achieve that goal is to minimize damage to the vessel walls. Sutures inevitably induce vascular wall damage, which influences the healing of the anastomosis. Over time, several alternatives to sutures have become available.

Methods
A Medline literature search was performed to locate English, German and French language articles pertinent to non-suture methods of vascular anastomosis. Manual cross-referencing was also performed and many historical articles were included.

Results and conclusion
The non-suture techniques can be categorized into five groups based on the materials used: rings, clips, adhesives, stents and laser welding. With all these techniques a faster and less traumatic anastomosis can be made compared with sutures. However, each device is associated with technique-related complications. As a consequence, suturing continues to be the standard approach. The disadvantages of the non-suture techniques include: rigidity and a non-compliant anastomosis with rings; toxicity, leakage and aneurysm formation with adhesives; early occlusion with stents; cost, reduced strength in larger-sized vessels and demand for surgical skills with laser welding. Further refinement is needed before widespread adoption of these techniques can occur. Clips, however, may be particularly promising but long-term evaluation is required.
Serum antigen(s) drive the proinflammatory T cell response in acute pancreatitis
Authors: Sweeney K J , Kell M R , Coates C , Murphy T , Reynolds J V 
Published: February 2003

Abstract

Background
Immune cells and cytokines are central to the systemic inflammatory response syndrome and multiple organ failure associated with acute pancreatitis. The specific role of T cells in this response is unclear, and this study focused on evaluating T cell activation and its regulation in patients with acute pancreatitis.

Methods
Peripheral blood samples of 14 patients with acute pancreatitis were obtained within 24 h of the onset of pain, within 48 h and at 1 week. T cell expression of surface markers CD69, CD62L and CD25 was measured. The production of interleukin (IL) 10 and IL-2 in vitro in response to the superantigen Staphylococcus enterotoxin B (SEB) was assessed. Serum samples from these patients were co-cultured with peripheral blood mononuclear cells from volunteers in the presence or absence of cytotoxic T lymphocyte-associated antigen (CTLA) 4 immunoglobulin, a specific inhibitor of antigen-dependent T cell activation.

Results
Expression of CD69 was significantly increased in CD3+ and CD4+ populations at 48 h and 1 week, and on CD8+ cells at 1 week. There was a significant increase in the production of SEB-induced IL-2 compared with findings in controls, but no significant IL-10 response. Serum from patients with pancreatitis activated normal T cells. This response was abolished completely by CTLA-4.

Conclusion
Acute pancreatitis results in the systemic activation of T cells. These cells are primed for a proinflammatory response to antigen stimulation and can be inhibited by antigen-specific T cell blockade. These data indicate that the immunoinflammatory response in acute pancreatitis is fuelled by one or more serum antigens and offer prospects for further understanding of the aetiogenesis of pancreatitis.
Bone marrow micrometastasis in breast cancer
Authors: Ozbas S , Dafydd H , Purushotham A D 
Published: February 2003

Abstract

Background
Several studies have demonstrated that bone marrow micrometastasis in patients with breast cancer is an independent prognostic factor for systemic recurrence and poorer survival.

Methods
This review describes the detection and clinical significance of micrometastatic cells in bone marrow, and examines the correlation between such micrometastasis and established clinicopathological prognostic factors. The relevant English language literature on bone marrow micrometastasis in breast cancer was searched via Medline (1975–2002), cross-referencing with key articles on the subject.

Results and conclusion
The balance of evidence favours the hypothesis that bone marrow micrometastasis impacts on disease-free and overall survival. Further prospective studies are required to examine this in greater detail, with particular reference to early node-negative breast cancer and the value of adjuvant systemic therapy in patients with bone marrow micrometastasis.
Identification of a sphincter at the sigmoidorectal canal in humans: Histomorphologic and morphometric studies
Authors: Shafik Ahmed , Asaad Soheir , Doss Sameh 
Published: February 2003

AbstractIn a recent study we demonstrated that the rectosigmoid junction is a large bowel segment 2.8 ± 0.9 cm in length, which we have termed the ‘sigmoidorectal canal’ (SRC). In that study we showed that the SRC exerted increased intraluminal pressure, contained a thick, circular, smooth muscle layer, and reacted to sigmoid colon (SC) and rectal contraction by relaxation and contraction, respectively. These findings suggest the existence of an anatomical sphincter at the SRC. To investigate this hypothesis, in the present study we carried out a morphometric (quantitative) analysis of the musculature of the SC, SRC, and rectum. Twenty‐two cadavers (13 male, 9 female; mean age = 32.3 ± 17.6 years) were investigated. Histomorphologic studies comprised staining transverse (15 cadavers) and longitudinal (7 cadavers) sections from the SC, SRC, and rectum. Specimens were stained with H&E, Masson's trichrome, and silver stains. Morphometric studies, using image analyzer computer equipment, measured the muscle thickness of the muscularis externa (ME) of the SC, SRC, and rectum. The ME of the SRC was markedly thickened compared to the ME of the SC or rectum. In 16 specimens, the increased thickness involved mainly the circular muscle layer and in six specimens both the circular and longitudinal layers. Connective tissue septa connected the adventitia with the submucosa: these ‘adventitial septa’ contained nerve ganglia. ‘Localized bundles’ of smooth muscle fibers were detected between the circular muscle fibers. The morphometric findings showed that the mean thickness of the circular muscle layer measured 440.3 ± 80.1 μm in the SC, 1166.1 ± 255.4 μm in the SRC, and 394.9 ± 123.9 μm in the rectum. This study strongly suggests the presence of an anatomic sphincter at the SRC. This sphincter may explain the higher pressure at the SRC and the response of the SRC to rectal and SC contractions. The localized smooth muscle bundles in the ME may represent a rectosigmoid pacemaker. Clin. Anat. 16:138–143, 2003. © 2003 Wiley‐Liss, Inc.
Variations in the number and position of human lumbar sympathetic ganglia and rami communicantes
Authors: Murata Yasuaki , Takahashi Kazuhisa , Yamagata Masatsune , Takahashi Yuzuru , Shimada Yutaka , Moriya Hideshige 
Published: February 2003

AbstractThe purpose of this study is to provide precise anatomical and statistical information about the number and location of lumbar sympathetic ganglia and the number and length of the related rami communicantes, and to consider the neurological pathway for nociception from the low back. Three‐hundred ninety‐three ganglia and 719 rami communicantes from 50 human cadavers were identified by gross dissection. The number of ganglia in a single lumbar chain ranged from 2 to 6, the mean being 3.9. The mean lengths of rami connected to the 1st and 5th lumbar spinal nerves, respectively, were significantly longer and shorter than those connected to the 2nd, 3rd, and 4th nerves. The lumbar sympathetic ganglia and rami communicantes were not distributed segmentally. The present results may assist in understanding the nociceptive pathway from the low back. Clin. Anat. 16:108–113, 2003. © 2003 Wiley‐Liss, Inc.
Topography of the pelvic autonomic nervous system and its potential impact on surgical intervention in the pelvis
Authors: Baader B. , Herrmann M. 
Published: February 2003

AbstractBladder, bowel, and sexual dysfunction caused by iatrogenic lesions of the inferior hypogastric plexus (IHP) are well known and commonly tolerated in pelvic surgery. Because the pelvic autonomic nerves are difficult to define and dissect in surgery, and their importance often ignored, we conducted a gross anatomic study of 90 adult and four fetal hemipelves. Using various non‐surgical approaches, the anatomic relations and pathways of the IHP were dissected. The IHP extended from the sacrum to the genital organs at the level of the lower sacral vertebrae. It originated from three different sources: the hypogastric nerve, the sacral splanchnic nerves from the sacral sympathetic trunk (mostly the S2 ganglion), and the pelvic splanchnic nerves, which branched primarily from the third and fourth sacral ventral rami. These fibers converge to form a uniform nerve plate medial to the vascular layer and deep to the peritoneum. The posterior portion of the IHP supplied the rectum and the anterior portion of the urogenital organs; nerve fibers traveled directly from the IHP to the anterolateral wall of the rectum and to the inferolateral and posterolateral aspects of the urogenital organs. The autonomic supply from the IHP was supplemented by nerves accompanying the ureter and the arteries. An understanding of the location of the autonomic pelvic network, including important landmarks, should help prevent iatrogenic injury through the adoption of surgical techniques that reduce or prevent postoperative autonomic dysfunction. Clin. Anat. 16:119–130, 2003. © 2003 Wiley‐Liss, Inc.
Seminar in breast self‐examination for female medical students integrated into a human gross anatomy course
Authors: Fischer V. , Pabst R. , Nave H. 
Published: February 2003

AbstractA breast self‐examination (BSE) seminar for first‐year female medical students is presented and a single‐gender approach for other subjects in the medical curriculum is discussed. In 1999 a small group seminar on BSE was offered at the Hannover Medical School to female medical students as part of their curriculum in human gross anatomy. An evaluation questionnaire was answered by 94 students (87% of participants). Frequencies of answers to two open questions were used as indicators of: 1) the acceptance of a single‐gender course and 2) an increased awareness of breast cancer prevention. A linear regression analysis was carried out to identify the most important predictors for the global course evaluation and a heightened interest in breast cancer prevention. The mean global rating of the seminar was 13.8 (minimum: 1 point; maximum: 15 points). Factors that significantly influenced the global rating were the course atmosphere, the teacher's enthusiasm, and the professional interest of the students. An increased concern for breast cancer prevention was significantly dependent on the professional interest and the self‐awareness of the women. The results suggest that there is a need for single‐gender seminars in academic medicine and that instruction of female students in BSE is an ideal subject for this approach. Because of the prevalence of breast cancer, it is recommended that such a seminar become an integral part of the preclinical curriculum for all female medical students. Clin. Anat. 16:160–164, 2003. © 2003 Wiley‐Liss, Inc.
Lumbar lordosis: Study of patients with and without low back pain
Authors: Murrie V.L. , Dixon A.K. , Hollingworth W. , Wilson H. , Doyle T.A.C. 
Published: February 2003

AbstractWe used magnetic resonance imaging (MRI) to assess lumbar lordosis in 27 patients with low back pain and 19 patients and 10 volunteers with no known back pain. Our study aimed to investigate whether lordosis changes with age and is reduced in those with low back pain. Although our results confirm known observations that lumbar lordosis is more prominent in women (P < 0.01) and those with a higher body mass index (P < 0.04), we were unable to demonstrate any significant variation in lordosis with age. Nor could we demonstrate any difference in the degree of lordosis among women with or without back pain. Men with low back pain tended to have a less prominent lordosis, but this difference did not reach statistical significance. Therefore, a ‘reduced lumbar lordosis’ should be regarded as a very weak clinical sign. Clin. Anat. 16:144–147, 2003. © 2003 Wiley‐Liss, Inc.