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Polyaddition reactions of N-hydroxy maleopimarimide with divinyl ether compounds were carried out to give novel polymers with ester acetal linkages in the main chain. The polymers have good solubility in common organic solvents and relatively high Tg temperatures. The number-average molecular weights of the polymers range from 4000 to 5500, with Mw/Mn of 1.7–2.3. The thermal decomposition temperatures of the polymers are above 220 °C. The film of the obtained polymers showed excellent transparency to UV light above 230 nm. The ester acetal linkage of the polymer chain can be cleaved in the presence of strong acid under mild heating. Making use of the high acidolytic activity of the polymers, positive-tone chemically amplified i-line photoresists can be formed from them and 2,1-diazonaphthoquinone-4-sulfonate, in which the well known photoactive compound can also function as a photoacid generator. The photolithographic performance of the photoresists was evaluated using an i-line exposure system with high photosensitivity and resolution.

Maleopimaric acid, cycloaddition reaction product of rosin with maleic anhydride, was reacted with hydroxylamine to afford N-hydroxy maleopimarimide, which was then further esterified with 2-diazo-1-naphthoquinone-4-sulfonyl chloride (2,1,4-DNQ-Cl) to give N-hydroxy maleopimarimide sulfonate. The carboxylic acid group of the compound was then protected by the reaction of this compound with vinyl ether compounds to give the corresponding molecular glass compounds. Upon irradiation to 365 nm light, the 2,1,4-DNQ group undergo photolysis not only to be converted into indene carboxylic acid but also generate a few amount of sulfonic acid which can catalyze the deprotection of the acid labile group. So, novel one-component positive-tone chemically amplified i-line photoresists can be formed by the molecular glass compounds. The lithographic performance of the resists was evaluated using i-line exposure system with high photosensitivity and resolution.

The oxidation behavior of (Mo 0.85 Nb 0.15 )Si 2 single crystals and the influence of Cr-addition were studied focusing on its microstructure dependence. Cr-addition to single-phase C40-structured (Mo 0.85 Nb 0.15 )Si 2 crystal induced the formation of crystalline silica, leading to slightly larger weight gain during the oxidation test at 1200 °C. Furthermore, Cr-addition to C40/C11 b duplex-phase (Mo 0.85 Nb 0.15 )Si 2 crystal with lamellar structure strongly suppressed the internal oxidation of the C11 b phase, resulting in excellent oxidation resistance. C40/C11 b lamellae-structured crystals showed better oxidation resistance than the C40-structured crystals.

To retrospectively determine the frequency and importance of a small amount of isolated pelvic free fluid seen at multidetector computed tomography (CT) in male patients who have blunt trauma without an identifiable cause.Institutional review board approval was obtained, and the requirement for informed consent was waived for this HIPAA-compliant study. One thousand male patients with blunt trauma who underwent abdominopelvic CT at a level 1 trauma center between January 2004 and June 2006 were entered into this study. The CT images of the 1000 patients were reviewed independently by two abdominal radiologists. CT scan assessment included evaluation for presence or absence of pelvic free fluid, any traumatic or nontraumatic cause of the free fluid, pelvic free fluid attenuation and volume measurements, and determination of the location of pelvic free fluid. Interobserver agreement was determined with kappa statistics, and the Student t test was used to assess differences in the mean volume and mean attenuation of the pelvic free fluid in the patients with and those without injury.Pelvic free fluid was identified in 10.2% (102 of 1000) of patients. A small amount of isolated pelvic free fluid without any identifiable cause was identified in 4.8% (48 of 1000) of patients by reader 1 and in 5.0% (50 of 1000) of patients by reader 2 (kappa value, 0.76) and was located at or below the level of the third sacral vertebral body in all 49 patients with isolated pelvic free fluid. The mean volume and mean attenuation of the small amount of isolated pelvic free fluid were 2.3 mL +/- 1.5 (standard deviation) and 8.1 HU +/- 3.9, respectively. None of the patients in this group had an undiagnosed bowel and/or mesenteric injury.In male patients with blunt trauma, a small amount of isolated pelvic free fluid with attenuation equal to that of simple fluid and located in the deep region of the pelvis likely is not a sign of bowel and/or mesenteric injury.

The floating zone growth of magneto-optical crystal YFeO3 has been investigated. The polycrystalline feed rod was prepared by a pressure of 250MPa and sintering at about 1500°C. A crack- free YFeO3 single crystal has been successfully grown. The crystal preferred to crystallize along direction with about 10° deviation. The X-ray rocking curve of the crystal has a FWHM of 24 arcsec, confirming the high crystal quality of the sample. The (100) plane was etched by hot phosphoric acid and the dislocation density was about 104/cm2. A thin outer layer with Y2O3-rich composition was found at the periphery of as-grown crystals, which was attributed to the Fe2O3 evaporation during growth. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

To determine the usefulness and potential pitfalls of helical computed tomography (CT) for depiction of normal anatomy and diagnosis of complications after gastric bypass surgery.From March 1998 to July 2002, 100 abdominal and pelvic CT examinations were performed in 72 patients after gastric bypass surgery for treatment of morbid obesity. Two of four attending abdominal radiologists retrospectively assessed the CT images in consensus for normal postoperative gastrointestinal anatomy and complications such as leaks, staple line dehiscence, bowel obstruction, abscess, hepatic or splenic infarction, and hernia. CT findings were compared with clinical, surgical, and other imaging findings.The gastric pouch, excluded stomach, proximal efferent loop, oversewn jejunal loop, and distal jejunojejunal anastomosis were identified in 96 (96%) of 100 studies and 69 (96%) of 72 patients, 100 (100%) of 100 studies and 72 (100%) of 72 patients, 99 (99%) of 100 studies and 71 (99%) of 72 patients, 88 (88%) of 100 studies and 61 (85%) of 72 patients, and 67 (67%) of 100 studies and 46 (64%) of 72 patients, respectively. The fundus of the excluded stomach was filled with a combination of air, fluid, and contrast material, which mimicked a loculated fluid collection in 15 (15%) of 100 studies and 13 (18%) of 72 patients. Sixty-two abnormalities, detected in 41 patients, included leak (n = 12), loculated fluid collection unrelated to leak (n = 9), markedly distended excluded stomach (n = 6), small-bowel obstruction (n = 6), gastric staple line dehiscence (n = 6), splenic infarction (n = 5), hematoma (n = 5), left hepatic lobe infarction (n = 3), and hernia related to gastric bypass (n = 10, including three internal hernias, three incisional hernias, and four nonincisional ventral hernias). Seventeen patients required a total of 21 CT-guided interventional procedures.Helical CT is useful for identifying normal postoperative anatomy and complications after gastric bypass surgery.

One in six males will develop prostate cancer during their lifetime. Prostate cancer is the second leading cause of cancer death in American males, behind only lung cancer. Unfortunately, even though this disease is so common, clinical screening methods such as prostate-specific antigen test and transrectal ultrasound-guided prostate biopsy lack sensitivity and specificity in diagnosing prostate cancer. In recent years, multiparametric prostate MRI has emerged as a very important tool in the diagnosis of prostate carcinoma with a high accuracy. However, diagnostic difficulty is often encountered even with an experienced abdominal radiologist. That is mainly because many normal and abnormal entities can mimic prostate carcinoma at multiparametric MRI. Therefore, the purpose of this pictorial review is to discuss the usefulness of multiparametric prostate MRI in the diagnosis of prostate carcinoma, emphasizing the key MRI features that help to make a distinction of prostate carcinoma from its mimics.

AIM: To determine the magnetic resonance cholangiopancreatography (MRCP) and magnetic resonance imaging (MRI) features of pancreatitis with pancreas divisum (PD) and the differences vs pancreatitis without divisum. METHODS: Institutional review board approval was obtained and the informed consent requirement was waived for this HIPAA-compliant study. During one year period, 1439 consecutive patients underwent successful MRCP without injection of secretin and abdominal MRI studies for a variety of clinical indications using a 1.5 T magnetic resonance scanner. Two experienced radiologists retrospectively reviewed all the studies in consensus. Disputes were resolved via consultation with a third experienced radiologist. The assessment included presence and the imaging findings of PD, pancreatitis, and distribution of abnormalities. The pancreatitis with divisum constituted the study group while the pancreatitis without divisum served as the control group. MRCP and MRI findings were correlated with final diagnosis. Fisher exact tests and Pearson × 2 tests were performed. RESULTS: Pancreatitis was demonstrated at MRCP and MRI in 173 cases (38 cases with and 135 cases without divisum) among the 1439 consecutive cases. The recurrent acute pancreatitis accounted for 55.26% (21 of 38) in pancreatitis patients associated with PD, which was higher than 6.67% (9 of 135) in the control group, whereas the chronic pancreatitis was a dominant type in the control group (85.19%, 115 of 135) when compared to the study group (42.11%, 16 of 38) (χ2 = 40.494, P < 0.0001). In cases of pancreatitis with PD, the dorsal pancreatitis accounted for a much higher percentage than that in pancreatitis without PD (17 of 38, 44.74% vs 30 of 135, 22.22%) (χ2 = 7.257, P < 0.05). CONCLUSION: MRCP and MRI can depict the features of pancreatitis associated with divisum. Recurrent acute pancreatitis and isolated dorsal involvement are more common in patients with divisum.

Multidetector computed tomography (MDCT) has emerged as the imaging modality of choice for evaluating the abdomen and pelvis in trauma patients. MDCT readily detects injury of the solid organs as well as direct and indirect features of bowel and/or mesenteric injury—an important advance given that unrecognized bowel and mesenteric injuries may result in high morbidity and mortality. Nonetheless, challenges persist in the interpretation of abdominal and pelvic CT images in trauma patients. Difficulty in interpretation may result from lack of familiarity with or misunderstanding of CT features of bowel and/or mesenteric injury. Moreover, due to major technical advances afforded by MDCT, new CT features of bowel and/or mesenteric injuries have been recognized. Beading and termination of mesenteric vessels indicating surgically important mesenteric injury is an example of one of these new features. MDCT also allows for the detection of small or trace amounts of isolated intraperitoneal fluid in trauma patients, although the clinical management of these patients is still controversial. This pictorial essay illustrates the spectrum of typical, atypical, and newly reported MDCT features of bowel and mesenteric injuries due to blunt trauma. The features that help to differentiate these injuries from pitfalls are emphasized in these proven cases.

Based on a 75t/h circulation fluidized bed biomass boiler with rice hull,wheat straw,maize straw and one kind of coal being fuel.The FLUENT software is used to simulate combustion process, temperature field, distribution of CO2 and O2 concentration with NOx emission.The results reveal that:temperature decreases gradually from bottom to upper and from center to periphery in the boiler.When the coal is combusted,the temperature is the highest.Comparing with boilers that burn coal,biomass boilers emit less NOx and there is the least NOx emission when rice hull is combusted.The results of this numerical simulation offer a reference to design and operation of circulation fluidized bed biomass boilers. Key word: biomass,circulation fluidized bed biomass boiler,combustion,numerical simulation. I.INTRODUCTION Biomass has aroused widespread interest in the world as new energy.To other fossil fuel,its merit includes little pollution,abundant,renewable.At the same time,circulation fluidized bed boilers have their own advantagements with broad compatibility of fuel,low pollutant emission and load adjusting easily.Therefore, circulation fluidized bed biomass boilers can drop combustion pollution to the lowest In this article,the FLUENT software is used to simulate the combustion process of a CFD biomass boiler with rice hull,wheat straw,maize straw and coal as fuel,respectively simulate temperature field,concentration distribution of CO2 and O2 and NOx prodution.The results are contrasted to analyse the difference of fuel and NOx production (4、7) .

As morbid obesity continues to increase in prevalence, bariatric surgery has become a popular treatment option. Radiologists must be aware of how to perform and interpret studies in this patient population. This article discusses the Roux-en-Y gastric bypass procedure including the expected postoperative findings on upper gastrointestinal examinations and CT and the potential complications that may occur.

Biochemical recurrence after treatment for prostate cancer (PCa) is a significant issue. Early diagnosis of local recurrence is important for making prompt treatment decisions and is strongly associated with patient prognosis. Without salvage therapy, the average time from development of local recurrence to distant metastasis is approximately 3 years. Biochemical recurrence does not differentiate local recurrence from systemic disease; there is no reliable way to clinically diagnose local recurrence. Recent advances in multiparametric MRI (mp-MRI) techniques have markedly improved detection of local recurrence following therapy. However, a wide variety of entities can mimic recurrent PCa at mp-MRI. Therefore, the purpose of this pictorial review is to discuss the MRI findings of locally recurrent PCa and its mimics, emphasizing the key MRI features that help to differentiate local recurrence from its mimics.

OBJECTIVE. The purpose of this article is to highlight the imaging features of congenital anomalies and normal variants of the pancreatic duct and the pancreas using contemporary imaging techniques such as MR cholangiopancreatography (MRCP), MRI, and helical CT.CONCLUSION. Congenital anomalies and normal variants of the pancreatic duct and the pancreas may be clinically significant and may create a diagnostic challenge. Recognition of the updated imaging features of these entities is important in clinical management and for avoiding misdiagnosis.

OBJECTIVE. The purpose of this article is to highlight the imaging features of congenital anomalies and normal variants of the biliary tract with contemporary imaging techniques such as MR cholangiopancreatography (MRCP), MRI, and helical CT.CONCLUSION. Recognizing findings of congenital anomalies and normal variants of the biliary tract at MRCP, MRI, and helical CT, and knowledge of the clinical significance of each entity, are important for establishing a correct diagnosis and in guiding appropriate clinical management.

To determine applicability of low-cost digital imaging for different radiographic modalities used in consultations from remote areas of the Ecuadorian rainforest with limited resources, both medical and financial. Low-cost digital imaging, consisting of hand-held digital cameras, was used for image capture at a remote location. Diagnostic radiographic images were captured in Ecuador by digital camera and transmitted to a password-protected File Transfer Protocol (FTP) server at VCU Medical Center in Richmond, Virginia, using standard Internet connectivity with standard security. After capture and subsequent transfer of images via low-bandwidth Internet connections, attending radiologists in the United States compared diagnoses to those from Ecuador to evaluate quality of image transfer. Corroborative diagnoses were obtained with the digital camera images for greater than 90% of the plain film and computed tomography studies. Ultrasound (U/S) studies demonstrated only 56% corroboration. Images of radiographs captured utilizing commercially available digital cameras can provide quality sufficient for expert consultation for many plain film studies for remote, underserved areas without access to advanced modalities.

The purpose of our pictorial essay is to present common mimics of appendicitis as noted on helical CT in patients with right lower quadrant pain and to highlight the features that provide clues to the diagnosis.Recognition of the findings of common diseases that simulate acute appendicitis on helical CT, along with features that help to differentiate these entities from appendicitis, is important in establishing a correct diagnosis and in guiding appropriate therapy.

PURPOSE: To compare 5- and 10-mm computed tomographic (CT) sections in the same patient to diagnose acute appendicitis. MATERIALS AND METHODS: During an 11-month period, 100 consecutive patients clinically suspected to have acute appendicitis underwent abdominal and pelvic CT. Helical, 10-mm-collimated sections from the diaphragm to the pubic symphysis and 5-mm-collimated sections through the lower part of the abdomen and upper part of the pelvis were obtained. The 10- and 5-mm sections from each patient were separated into two groups and were interpreted independently by two abdominal imaging attending physicians who were blinded to the final results. The interpretations were correlated with the histopathologic or final clinical diagnoses. RESULTS: Data analysis from blinded reader interpretations of the 5- and 10-mm sections, respectively, revealed sensitivities of 99% and 82% (P

Multiparametric-MRI is an important tool in the diagnosis of prostate cancer (PCa), particularly diffusion-weighted imaging for peripheral zone (PZ) cancer in the untreated prostate. However, there are many benign entities that demonstrate diffusion restriction in the PZ mimicking PCa resulting in diagnostic challenges. Fortunately, these benign entities usually have unique MR features that may help to distinguish them from PCa. The purpose of this pictorial review is to discuss benign entities with diffusion restriction in the PZ and to emphasize the key MR features of these entities that may help to differentiate them from PCa.