bluuebunny/crossref_metadata_2025_split huggingface dataset:
Percutaneous Endoscopic Interlaminar Discectomy for Intracanalicular Disc Herniations At L5–S1 Using a Rigid Working Channel Endoscope
Authors: Choi Gun , Lee Sang-Ho , Raiturker Pradyumna Pai , Lee Seungcheol , Chae Yu-Sik 
Published: February 2006

AbstractOBJECTIVE:Percutaneous endoscopic transforaminal discectomy is often used as a minimally invasive procedure for lumbar disc herniation. However, a transforaminal approach posts limitations at the L5–S1 level owing to anatomic constraints, such as a high iliac crest or small intervertebral foramen and especially for migrated large intracanalicular disc herniations. We discuss the procedure and clinical results of percutaneous endoscopic interlaminar discectomy using a rigid working channel endoscope at the L5–S1 level and the relevant surgical anatomy.METHODS:We performed percutaneous endoscopic discectomy through the interlaminar approach in 67 patients who satisfied our inclusion criteria during the period from March 2002 to November 2002. All procedures were performed under local anesthesia. Under fluoroscopic guidance, we performed discography using indigocarmine mixed with radio-opaque dye. The 6-mm working channel endoscope was then introduced into the epidural space. Herniated disc material was removed using forceps and laser under clear endoscopic visualization. We retrospectively evaluated the 65 cases with more than 1.5 years of follow-up. The patients were evaluated using the visual analogue scale (VAS) and the Oswestry Disability Index (ODI).RESULTS:VAS for leg pain (preoperative mean, 7.89; postoperative mean, 1.58) and ODI (preoperative mean, 57.43; postoperative mean, 11.52) showed statistically significant (P = 0.00) improvement in their values at the last follow-up examination compared with preoperative scores. Of the study group, 90.8% individuals showed favorable result. The mean hospital stay was 12 hours. The average time to return to work was 6.79 weeks. Complications included two cases of dural injury with cerebrospinal fluid leakage, nine cases of dysesthesia that were transient, and one case of recurrence. Two patients required conversion to open procedure at the initial operation. There was no evidence of infection in any patients.CONCLUSION:Percutaneous endoscopic interlaminar discectomy is a safe, effective, and minimally invasive procedure for the treatment of intracanalicular disc herniations at the L5–S1 level in properly selected cases, especially when the transforaminal approach is not possible because of anatomic constraints.
Scalp to Meningeal Arterial Anastomosis in the Parietal Foramen
Authors: Yoshioka Nobutaka , Rhoton Albert L. , Abe Hiroshi 
Published: February 2006

Abstract

OBJECTIVE:
The purpose of this study was to examine the parietal foramen and to determine whether it is the site of an anastomosis between the meningeal and scalp arteries.

METHODS:
Forty parietal regions from 20 adult cadavers, in which the arteries were perfused with colored latex, were examined for this study. The scalp was separated from the parietal foramen, and the vasculature in the foramen and adjacent scalp and dura were examined using ×3 magnification. The scalp arteries that anastomosed with the meningeal arteries through the parietal foramen were followed into the dura after craniotomy.

RESULTS:
Parietal foramen was found in 20 of the 40 (50%) parietal regions. They were present bilaterally in eight heads and unilaterally in four. Every parietal foramen transmitted an anastomosis between the middle meningeal and scalp arteries. In 11 (55%) of the 20 foramina found in this study, the superficial temporal and occipital artery formed an anastomosis in the galea and pericranial layer that sent a branch through the parietal foramen to anastomose with parietal branches of the middle meningeal artery. In the remaining nine (45%) sides, the middle meningeal artery had a connection through the foramen with a small pericranial artery.

CONCLUSION:
Every parietal foramen was the site of a connection between the middle meningeal and scalp arteries. The scalp end of the anastomosis most commonly arose in an anastomosis between the superficial temporal and occipital arteries. This anastomosis may be involved in several pathologies.
Comparative Analysis of Anterior Petrosectomy and Transcavernous Approaches to Retrosellar and Upper Clival Basilar Artery Aneurysms
Authors: Figueiredo Eberval Gadelha , Zabramski Joseph M. , Deshmukh Puspha , Crawford Neil R. , Spetzler Robert F. , Preul Mark C. 
Published: February 2006

Abstract

OBJECTIVE:
To compare two techniques, transcavernous approach (TcA) and anterior petrosectomy (AP), used to manage retrosellar and upper clival basilar artery (BA) aneurysms.

METHODS:
AP and TcA were carried out on nine sides of cadaver heads. With use of a computerized tracking system, the area of surgical exposure in the ventral surface of the brain stem, the superficial area of exposure, and the linear exposure of the BA were evaluated. The angles of approach in the horizontal and vertical axes were measured using a robotic microscope. The caudal extent of exposure was determined by an aneurysm clip applied to proximal BA, and the distance between the clip and the floor of the sella was quantified after performing TcA.

RESULTS:
TcA (1127.3 ± 438.4 mm2) provided a greater superficial exposure than AP (697.7 ± 219.1 mm2) (P = 0.01). There were no statistical differences in the deep working exposure (P = 0.303) between TcA (206.9 ± 40.7 mm2) and AP (260.2 ± 137.1 mm2). The linear exposure of the BA was greater for AP (22.7 ± 6.2 mm2) than for the TcA (12.8 ± 2.9 mm2) (P = 0.004). The caudal extent of exposure averaged 6.1 mm from the floor of the sella. No differences were found in horizontal angles (P = 0.596); however, vertical angles were significantly greater for the TcA than AP (15.2 ± 3.4) (P = 0.004).

CONCLUSION:
From an anatomic standpoint, the TcA offers more advantages than the AP, when approaching retrosellar BA aneurysms, except for those cases in which proximal control is the principal issue and the neck of the aneurysm is located more than 6.0 mm below the floor of the sella.
Endoscopic Transsphenoidal Pituitary Surgery with Intraoperative Magnetic Resonance Imaging
Authors: Schwartz Theodore H. , Stieg Phillip E. , Anand Vijay K. 
Published: February 2006

Abstract

OBJECTIVE:
The two most recent significant advances in pituitary surgery have been the endonasal endoscopic approach and intraoperative magnetic resonance imaging (IMRI). Each provides improved visualization of intra- and parasellar anatomy with the goal of attaining a complete resection. The combination of the two techniques has not been previously reported in the literature.

METHODS:
We performed endoscopic, endonasal resection of pituitary macroadenomas in 15 patients using the Polestar N-10 (0.12T) IMRI (Odin Medical Technologies, Inc., Newton, MA). Eleven patients had nonfunctioning tumors, three had acromegaly, and one had a medication-resistant prolactinoma. The effect of the magnetic field on the cathode ray tube screen and the image quality of the IMRI images were assessed. The presence of residual tumor on IMRI was noted and then re-examined with the endoscope.

RESULTS:
Although the Polestar N-10 is a low Tesla magnet, the IMRI caused significant distortion of the cathode ray tube screen regardless of the viewing angle. This was overcome with the use of a wall-mounted plasma screen. IMRI images were obtained in all cases and were of sufficiently high quality to demonstrate adequate decompression of the optic chiasm and the removal of all suprasellar tumor. In three cases, residual tumor was found with IMRI that was resected endoscopically before the completion of surgery. In four other cases, potential residual tumor was examined endoscopically and found to be normal postoperative change. In eight cases no residual intrasellar tumor was seen on the IMRI. Preresection visual deficits improved in all cases and the insulin-like growth factor levels normalized in two of three cases. There were no delayed cerebrospinal fluid leaks.

CONCLUSION:
Combining intraoperative endoscopy and IMRI is feasible and distortion of the cathode ray tube screen can be overcome with the use of either a plasma or liquid crystal display screen. Each technology provides complementary information, which can assist the surgeon in safely maximizing the extent of resection. In this small series using a low-field magnet, rates of residual tumor following endoscopic trans-sphenoidal surgery were less than have been reported following microscope-based transsphenoidal surgery.
The crystal and molecular structures of sodium and barium complexes of dibenzo-24-crown-8 ether
Authors: Schilde Uwe , Erk Çakil , Kleinpeter Erich 
Published: February 2006

Abstract
The sodium and barium isothiocyanate complexes of 6,7,9,10,12,13,20,21,23,24,26,27-dodecahydro-dibenzo[b,n]-1,4,7,10,13,16,19,22-octaoxacyclotetracosin (dibenzo-24-crown-8 ether=DB24C8) were synthesized and analyzed by X-ray diffraction.
The sodium complex, [Na(DB24C8)(NCS)(H2O)] 1, crystallizes in the orthorhombic space group Fdd2 with 16 molecules in the unit cell. The coordination number of Na is 6 and the central ion is located in a distorted octahedric environment. Only four of the crown ether oxygen atoms are involved. The coordination polyhedron is completed by the isothiocanate anion and by a water molecule, which is stabilized by hydrogen bonds.
The barium complex, [Ba(DB24C8)(NCS)2] 2, crystallizes in the trigonale space group P3121 with 3 molecules in the unit cell. Crystallographic C2 symmetry is observed for the complex. The coordination number of Ba is 10. Barium is coordinated with the eight oxygen atoms of the macrocyclic ligand and with two isothiocyanate anions. The absolute structure was estimated using the FLACK parameter.
Involvement of Niemann-Pick Type C2 Protein in Hematopoiesis Regulation
Authors: Heo Kyu , Jariwala Unnati , Woo Jeongim , Zhan Yuxia , Burke Kathleen A. , Zhu Lunjian , Anderson W. French , Zhao Yi 
Published: February 2006

Abstract
Niemann-Pick type C2 (NPC2) protein has been characterized as a cholesterol-binding protein. Its loss leads to NPC2 disease, an inherited neurodegenerative disorder. When analyzing gene expression profile, we noticed high expression of both NPC2 and its receptor, mannose 6-phosphate receptor (MPR), in murine hematopoietic stem cells. NPC2 protein, in the presence of thrombopoietin (TPO), causes an increase in CFU-GEMM (colony-forming unit-granulocyte-erythroid-macrophage-megakaryocyte) and a decrease in CFU-GM (colony-forming unit-granulocyte-macrophage) colony number in colony-forming cell (CFC) assays. This effect is independent of cholesterol binding but does require the presence of MPR. With M07e cells, a TPO-dependent hematopoietic leukemia cell line, NPC2 can inhibit TPO-induced differentiation and enhance TPO-mediated anti-apoptosis effects. Strikingly, these results are not observed under the standard 20% O2 level of the standard incubator, but rather at 7% O2, the physiological oxygen level of bone marrow. Furthermore, NPC2 protein upregulates hypoxia inducible factor 1-α protein level at 7% O2, but not at 20% O2. Our results demonstrate that NPC2 protein plays a role in hematopoiesis at the physiologic bone marrow level of O2.
Regulatory Agencies
Authors: Passow Nancy R. , Yingling Gary L. , Onel Suzan 
Published: February 2006

AbstractBecause of updates and reauthorization, regulations covering health, safety, and environmental issues change continuously and specifications can become outdated. Regulatory agencies provide assistance regarding the laws and regulations of these issues. The two main federal agencies involved in the protection of human health and the environment are the Environmental Protection Agency (EPA) and the Occupational Safety and Health Administration (OSHA). Primary laws covered by the EPA are the Clean Air Act Amendments (CAAA); the Clean Water Act (CWA); Resource Conservation and Recovery Act (RCRA); Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA); Toxic Substances Control Act (TSCA); and the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). The principal function of OSHA is the protection of people in the workplace. Other functions of regulatory agencies, eg, agriculture, commerce, defense, and energy, are discussed.The Food and Drug Administration (FDA) is the primary federal scientific and regulatory government agency that monitors drug, biologic, medical device, food, veterinary and cosmetic products. FDA is organized into five distinct centers, each with its own rules and regulations. This article discusses FDA’s traditional regulatory mission of consumer protection and how its decisional processes have changed over time as a result of the explosion of advances within analytical chemistry and toxicology. Because no compound is completely safe, FDA must regularly assess the intended use of a product and whether the level of risk is acceptable. The article also summarizes the legislation that sets the boundaries of FDA’s authority and lays out the administration’s organization and responsibilities.The chemical process industry is highly regulated in the environmental, health, and safety area. Everything is affected, from the siting of a new facility to the transportation of raw materials and finished products, from the working conditions for employees to operating requirements for processes, packaging of finished goods, and dealings with the community. The two main U.S. Federal agencies involved in the protection of human health and the environment are the Environmental Protection Agency (EPA) and the Occupational Safety and Health Administration (OSHA). The EPAs principal concern is the protection of the environment; in most cases, the area outside of an industrial facility. Significant laws covered by EPA are discussed.
Posterior hypothalamic activation in paroxysmal hemicrania
Authors: Matharu Manjit S. , Cohen Anna S. , Frackowiak Richard S. J. , Goadsby Peter J. 
Published: February 2006

AbstractObjectiveParoxysmal hemicrania (PH) is a severe, strictly unilateral headache that lasts 2 to 30 minutes, occurs more than five times daily, is associated with trigeminal autonomic symptoms, and is exquisitely responsive to indomethacin. The purpose of the study was to determine the brain structures active in PH.MethodsSeven PH patients were studied using positron emission tomography (PET). Each patient was scanned in three states: (1) acute PH attack–off indomethacin; (2) pain‐free–off indomethacin; and (3) pain‐free after administration of intramuscular indomethacin 100mg. The scan images were processed and analyzed using SPM99.ResultsThe study showed no significant activations during state 1 compared with state 2, but there was relative activation of the pain neuromatrix in both states 1 and 2 compared with state 3. This suggests that there is persistent activation of the pain neuromatrix during acute PH attacks and during interictal pain‐free states off indomethacin that is deactivated by the administration of indomethacin. In addition, the untreated PH state was associated with significant activation of the contralateral posterior hypothalamus and contralateral ventral midbrain, which extended over the red nucleus and the substantia nigra.InterpretationThese activated subcortical structures may play a pivotal role in the pathophysiology of this syndrome. Ann Neurol 2006;59:535–545
Synthesis and characterization of poly(thiophen‐3‐yl acetic acid 4‐pyrrol‐1‐yl phenyl ester‐co‐N‐methylpyrrole) and its application in an electrochromic device
Authors: Bingöl Bahar , Camurlu Pinar , Toppare Levent 
Published: February 2006

AbstractCopolymer of thiophen‐3‐yl acetic acid 4‐pyrrol‐1‐yl phenyl ester (TAPE) with N‐methylpyrrole (NMPy) was synthesized by potentiostatic electrochemical polymerization in acetonitrile–tetrabutylammonium tetrafluoroborate solvent–electrolyte couple. The chemical structures were confirmed via Fourier transform infrared spectroscopy (FTIR), cyclic voltammetry (CV), and UV–vis spectroscopy. Electrochromic and spectroelectrochemical properties of poly(TAPE‐co‐NMPy) [P(TAPE‐co‐NMPy)] were investigated. Results showed that the copolymer revealed color change between light yellow and green upon doping and dedoping of the copolymer, with a moderate switching time. Furthermore, as an application, dual‐type absorptive/transmissive polymer electrochromic device (ECD) based on poly(TAPE‐co‐NMPy) and poly(3,4‐ethylene dioxythiophene) (PEDOT) have been assembled, where spectroelectrochemistry, switching ability, stability, and optical memory of the ECD were investigated. Results showed that the device exhibited good optical memory and stability with moderate switching time. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1988–1994, 2006
Three‐dimensional solubility parameters of poly(ε‐caprolactone)
Authors: Huang Jan‐Chan , Lin Ko‐Ting , Deanin Rudolph D. 
Published: February 2006

AbstractThe three‐dimensional solubility parameter model was applied to analyze solution thermodynamic data of 27 solutes in poly(ε‐caprolactone) (PCL) between 70 and 110 °C. A linear regression method was compared with a nonlinear least square regression method, which searches solubility parameter components by minimization of the sum of error squares. The parameters of polymers were the same by both methods. When compared with the error in predicting χRT/V, the data showed a different slope from the simple three‐dimensional model. These deviations were reduced by a different model using a smaller weight on the polar and hydrogen bonding components. In the new model, the solubility parameter components were closer to the value of a structure analogue of PCL. The confidence intervals for the parameters were estimated from a linearized equation based on the sum of error squares. The solubility parameter components obtained were different from the average values of the five solutes with the smallest χ. The inclusion of solutes with high hydrogen bonding components contributed to the increase of the component in the nonlinear regression method. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2002–2009, 2006
Microwave‐irradiated ring‐opening polymerization of D,L‐lactide under atmosphere
Authors: Jing Shu , Peng Wang , Tong Zheng , Baoxiu Zhao 
Published: February 2006

AbstractPoly(D,L‐lactide) (PDLLA) was synthesized by microwave‐irradiated ring‐opening polymerization catalyzed by stannous octoate (Sn(Oct)2) under atmosphere. The effects of heating medium, monomer purity, catalyst concentration, microwave irradiation time, and vacuum level were discussed. Under the appropriate conditions such as carborundum (SiC) as heating‐medium, 0.15% catalyst, lactide with purity above 99.9%, 450 W microwave power, 30 min irradiation time, and atmosphere, PDLLA with a viscosity–average molecular weight (Mη) over 2.0 × 105 and a yield over 85% was obtained. The dismission of vacuum to ring‐opening polymerization of D,L‐lactide (DLLA) under microwave irradiation simplified the process greatly. The temperature under microwave irradiation and conventional heating was compared. The largely enhanced ring‐opening polymerization rate of DLLA under microwave irradiation was the coeffect of thermal effects and microwave effects. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2244–2247, 2006
Separation characteristics of acetic acid–water mixtures by using poly(vinyl alcohol‐g‐4‐vinyl pyridine) membranes by pervaporation and temperature difference evapomeation techniques
Authors: Asman Gülsen , şanlı Oya 
Published: February 2006

AbstractThe separation of acetic acid–water mixtures was carried by using pervaporation (PV) and temperature difference evapomeation (TDEV) methods. For the separation process 4‐vinyl pyridine was grafted on poly(vinyl alcohol). Membranes were prepared from the graft‐copolymer by casting method and crosslinked by heat treatment. The effect of feed composition on the separation characteristics was studied and the performances of the separation methods were compared. Permeation rates obtained in PV were found to be high, whereas separation factors were high in TDEV method. Membranes gave permeation rates of 0.1–3.0 kg/(m2 h) and separation factors of 2.0–61.0, depending on the composition of the feed mixture and the method. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2030–2039, 2006
Synthesis and characterization of negative‐type polyamic acid ester with 1‐methacryloyloxy‐2‐propanoate group
Authors: Choi Sung Mook , Kwon Soo‐Han , Yi Mi Hye 
Published: February 2006

AbstractA negative‐type photosensitive polyamic acid (PAA) was synthesized from cyclobutane‐1,2,3,4‐tetracarboxylic dianhydride and 2‐(methacryloyloxy)ethyl 3,5‐diaminobenzoate in N‐methyl‐2‐pyrrolidinone. Glycidyl methacrylate was added into the PAA solution to yield a photosensitive PAA ester (PAE) by the ring‐opening esterification reaction of the carboxylic acid group in the PAA and glycidyl methacrylate. Esterification reactions were conducted with varying reaction temperatures and times. The typical PAE (PAE‐C3) with a degree of esterification of 20% was used for a photosensitivity study. We investigated the effects of the postexposure baking temperature, amount of photoinitiator, and exposure dose on the photosensitivity of PAE‐C3. Furthermore, a photolithography evaluation was conducted on PAE‐C3 in the presence of 1‐[4‐(phenylthio)phenyl]‐2‐(O‐benzoyloxime)‐1,2‐octanedione as a photoinitiator using a mercury lamp at a 365‐nm wavelength. The resolution of the film with 2.0‐μm thickness was about 8 μm. PAE‐C3 cured at 250°C for 60 min was stable up to around 310°C in a nitrogen atmosphere. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2252–2258, 2006
Loading rate effects on mechanical properties of polymer composites at ultralow temperatures
Authors: Ray Bankim Ch. 
Published: February 2006

AbstractE‐glass fibers of 55, 60, and 65 weight percentages were reinforced with epoxy matrix to prepare the laminated composites. They were exposed to −40, −60, and −80°C temperatures for different times. The 3‐piont bend test was conducted on the conditioned samples at those temperatures. Mechanical test was carried out at 2 mm/min and 500 mm/min crosshead speeds. The main emphasis of the investigation was to evaluate the roles of percentage matrix phase and interfacial areas on the interlaminar shear failure mechanism of glass/epoxy composites at ultralow temperatures for different loading speeds. The mechanical performances of the laminated specimens at low temperatures were compared with room temperature property. The loading rate sensitivity of the polymer composites appeared to be inconsistent and contradictory at some points of conditioning time and as well as at a temperature of conditioning. This Phenomenon may be attributed to low‐temperature hardening, matrix cracking, misfit strain due to differential thermal coefficient of the constituent phases, and also to enhanced mechanical keying factor by compressive residual stresses at low temperatures. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2289–2292, 2006