bluuebunny/crossref_metadata_2025 huggingface dataset:
A multi-sensor upper tropospheric ozone product (MUTOP) based on TES ozone and GOES water vapor: validation with ozonesondes
Authors: Moody J. L. , Felker S. R. , Wimmers A. J. , Osterman G. , Bowman K. , Thompson A. M. , Tarasick D. W.
Published: June 2012

Abstract. Accurate representation of ozone in the extratropical upper troposphere (UT) remains a challenge. However, the implementation of hyper-spectral remote sensing using satellite instruments such as the Tropospheric Emission Spectrometer (TES) provides an avenue for mapping ozone in this region, from 500 to 300 hPa. As a polar orbiting satellite TES observations are limited, but in this paper they are combined with geostationary satellite observations of water vapor. This paper describes a validation of the Multi-sensor UT Ozone Product (MUTOP). MUTOP, based on a statistical retrieval method, is an image product derived from the multiple regression of remotely sensed TES ozone, against geostationary (GOES) specific humidity (remotely sensed) and potential vorticity (a modeled dynamical tracer in the UT). These TES-derived UT ozone mixing ratios are compared to coincident ozonesonde measurements of layer-average UT ozone mixing ratios made during the NASA INTEX/B field campaign in the spring of 2006; the region for this study is effectively the GOES west domain covering the eastern North Pacific Ocean and the western United States. This intercomparison evaluates MUTOP skill at representing ozone magnitude and variability in this region of complex dynamics. In total, 11 ozonesonde launch sites were available for this study, providing 127 individual sondes for comparison; the overall mean ozone of the 500–300 hPa layer for these sondes was 78.0 ppbv. MUTOP reproduces in~situ measurements reasonably well, producing an UT mean of 82.3 ppbv, with a mean absolute error of 12.2 ppbv and a root mean square error of 16.4 ppbv relative to ozonesondes across all sites. An overall UT mean bias of 4.3 ppbv relative to sondes was determined for MUTOP. Considered in the context of past TES validation studies, these results illustrate that MUTOP is able to maintain accuracy similar to TES while expanding coverage to the entire GOES-West satellite domain. In addition MUTOP provides six-hour temporal resolution throughout the INTEX-B study period, making the visualization of UT ozone dynamics possible. This paper presents the overall statistical validation as well as a selection of ozonesonde case studies. The case studies illustrate that error may not always represent a lack of TES-derived product skill, but often results from discrepancies driven by observations made in the presence of strong meteorological gradients.
Wintertime Arctic Ocean sea water properties and primary marine aerosol concentrations
Authors: Zábori J. , Krejci R. , Ekman A. M. L. , Mårtensson E. M. , Ström J. , de Leeuw G. , Nilsson E. D.
Published: June 2012

Abstract. Sea spray aerosols are an important part of the climate system through their direct and indirect effects. Due to the diminishing sea ice, the Arctic Ocean is one of the most rapidly changing sea spray aerosol source areas. However, the influence of these changes on primary particle production is not known. In laboratory experiments we examined the influence of Arctic Ocean water temperature, salinity and oxygen saturation on primary particle concentration characteristics. Sea water temperature was identified as the most important of these parameters. A strong decrease in sea spray aerosol production with increasing water temperature was observed for water temperatures between −1 °C and 9 °C. Aerosol number concentrations decreased from at least 1400 cm−3 to 350 cm−3. In general, the aerosol number size distribution exhibited a robust shape with one mode close to Dp 0.2 μm with approximately 45% of particles at smaller sizes. Changes in sea water temperature did not result in pronounced change of the shape of the aerosol size distribution, only in the magnitude of the concentrations. Our experiments indicate that changes in aerosol emissions are most likely linked to changes of the physical properties of sea water at low temperatures. The observed strong dependence of sea spray aerosol concentrations on sea water temperature, with a large fraction of the emitted particles in the typical cloud condensation nuclei size range, provide strong arguments for a more careful consideration of this effect in climate models.
Development of a new data-processing method for SKYNET sky radiometer observations
Authors: Hashimoto M. , Nakajima T. , Dubovik O. , Campanelli M. , Che H. , Khatri P. , Takamura T. , Pandithurai G.
Published: June 2012

Abstract. In order to reduce uncertainty in the estimation of aerosol direct radiative forcing (DARF), it is important to improve the estimation of the single scattering albedo (SSA). In this study, we propose a new data-processing method to improve SSA retrievals for the SKYNET sky radiometer network, which is one of the growing number of networks of sun-sky photometers, such as NASA AERONET and others. There are several reports that SSA values from SKYNET have a bias compared to those from AERONET, which is regarded to be the most accurate due to its rigorous calibration routines. We investigated possible causes of errors in SSA that might explain the known biases through sensitivity experiments using a numerical model, and also using real data at the SKYNET sites at Pune (18.616° N/73.800° E) in India and Beijing (39.586° N/116.229° E) in China. Sensitivity experiments showed that an uncertainty of the order of ±0.03 in the SSA value can be caused by a possible error in the ground surface albedo or solid view angle assumed for each observation site. Another candidate for possible error in the SSA was found in cirrus contamination generated by imperfect cloud screening in the SKYNET data processing. Therefore, we developed a new data quality control method that eliminates these error sources, and we applied this method to the real observation data at the Pune site in SKYNET. After applying this method to the observation data, we were able to screen out a large amount of cirrus-contaminated data and to reduce the deviation in the SSA value from that of AERONET. We then estimated DARF using data screened by our new method. The result showed that the method significantly reduced the difference of 5 W m−2 that existed between the SKYNET and AERONET values of DARF before screening. The present study also suggests the necessity of preparing suitable a priori information on the distribution of coarse particles ranging in radius between 10 μm and 30 μm for the analysis of heavily dust-laden atmospheric cases.
A global compilation of dissolved iron measurements: focus on distributions and processes in the Southern Ocean
Authors: Tagliabue A. , Mtshali T. , Aumont O. , Bowie A. R. , Klunder M. B. , Roychoudhury A. N. , Swart S.
Published: June 2012

Abstract. Due to its importance as a limiting nutrient for phytoplankton growth in large regions of the world's oceans, ocean water column observations of concentration of the trace-metal iron (Fe) have increased markedly over recent decades. Here we compile >13 000 global measurements of dissolved Fe (dFe) and make this available to the community. We then conduct a synthesis study focussed on the Southern Ocean, where dFe plays a fundamental role in governing the carbon cycle, using four regions, six basins and five depth intervals as a framework. Our analysis highlights depth-dependent trends in the properties of dFe between different regions and basins. In general, surface dFe is highest in the Atlantic basin and the Antarctic region. While attributing drivers to these patterns is uncertain, inter-basin patterns in surface dFe might be linked to differing degrees of dFe inputs, while variability in biological consumption between regions covaries with the associated surface dFe differences. Opposite to the surface, dFe concentrations at depth are typically higher in the Indian basin and the Subantarctic region. The inter-region trends can be reconciled with similar ligand variability (although only from one cruise), and the inter-basin difference might be explained by differences in hydrothermal inputs suggested by modelling studies (Tagliabue et al., 2010) that await observational confirmation. We find that even in regions where many dFe measurements exist, the processes governing the seasonal evolution of dFe remain enigmatic, suggesting that, aside from broad Subantarctic – Antarctic trends, biological consumption might not be the major driver of dFe variability. This highlights the apparent importance of other processes such as exogenous inputs, physical transport/mixing or dFe recycling processes. Nevertheless, missing measurements during key seasonal transitions make it difficult to better quantify and understand surface water replenishment processes and the seasonal Fe cycle. Finally, we detail the degree of seasonal coverage by region, basin and depth. By synthesising prior measurements, we suggest a role for different processes and highlight key gaps in understanding, which we hope can help structure future research efforts in the Southern Ocean.
Spatial and temporal variability of biophysical variables in southwestern France from airborne L-band radiometry
Authors: Zakharova E. , Calvet J.-C. , Lafont S. , Albergel C. , Wigneron J.-P. , Pardé M. , Kerr Y. , Zribi M.
Published: June 2012

Abstract. In 2009 and 2010 the L-band microwave Cooperative Airborne Radiometer for Ocean and Land Studies (CAROLS) campaign was performed in southwestern France to support the calibration and validation of the new Soil Moisture and Ocean Salinity (SMOS) satellite mission. The L-band Microwave Emission of the Biosphere (L-MEB) model was used to retrieve surface soil moisture (SSM) and the vegetation optical depth (VOD) from the CAROLS brightness temperature measurements. The CAROLS SSM was compared with in situ observations at 11 sites of the SMOSMANIA (Soil Moisture Observing System-Meteorological Automatic Network Integrated Application) network of Météo-France. For eight of them, significant correlations were observed (0.51 ≤ r ≤ 0.82), with standard deviation of differences ranging from 0.039 m3 m−3 to 0.141 m3 m−3. Also, the CAROLS SSM was compared with SSM values simulated by the A-gs version of the Interactions between Soil, Biosphere and Atmosphere (ISBA-A-gs) model along 20 flight lines, at a resolution of 8 km × 8 km. A significant spatial correlation between these two datasets was observed for all the flights (0.36 ≤ r ≤ 0.85). The CAROLS VOD presented significant spatial correlations with the vegetation water content (VWC) derived from the spatial distribution of vegetation types used in ISBA-A-gs and from the Leaf Area Index (LAI) simulated for low vegetation. On the other hand, the CAROLS VOD presented little temporal changes, and no temporal correlation was observed with the simulated LAI. For low vegetation, the ratio of VOD to VWC tended to decrease, from springtime to summertime. The ISBA-A-gs grid cells (8 km × 8 km) were sampled every 5 m by CAROLS observations, at a spatial resolution of about 2 km. For 83% of the grid cells, the standard deviation of the sub-grid CAROLS SSM was lower than 0.05 m3 m−3. The presence of small water bodies within the ISBA-A-gs grid cells tended to increase the CAROLS SSM spatial variability, up to 0.10 m3 m−3. Also, the grid cells characterised by a high vegetation cover heterogeneity presented higher standard deviation values, for both SSM and VOD.
Climate change impact on groundwater levels: ensemble modelling of extreme values
Authors: Kidmose J. , Refsgaard J. C. , Troldborg L. , Seaby L. P. , Escrivà M. M.
Published: June 2012

Abstract. This paper presents a first attempt to estimate future groundwater levels by applying extreme value statistics on predictions from a hydrological model. Climate for the future period, 2081–2100, are represented by projections from nine combinations of three global climate models and six regional climate models, and downscaled with two different methods. An integrated surface water/groundwater model is forced with precipitation, temperature, and evapotranspiration from the 18 model – and downscaling combinations. Extreme value analyses are performed on the hydraulic head changes from a control period (1991–2010) to the future period for the 18 combinations. Hydraulic heads for return periods of 21, 50 and 100 yr (T21–100) are estimated. Three uncertainty sources are evaluated; climate models, downscaling and extreme value statistics. Of these sources, downscaling dominates for the higher return periods of 50 and 100 yr, whereas uncertainty from climate models and downscaling are similar for lower return periods. Uncertainty from the extreme value statistics only contribute up to around 10% of the uncertainty from the three sources.
Are They Really Similar? Satisfaction, Opinion, and Scholarly Activity of Black Faculty by Citizenship Status
Authors: Boyer Patricia G , Holtman Lorna
Published: June 2012

Faculty workload is an important higher education issue because of its increasing demands on faculty time, mandates by institutional and external factors, and its relationship to job satisfaction. Specifically, how faculty perceive their workload can positively or negatively influence their job satisfaction. Current literature regarding faculty and workload has focused largely on workload models. The purpose of this study was to evaluate the workload of Black faculty members by citizenship status (U.S. citizens; citizens, foreign born; and non-citizens) based on satisfaction, opinion, and scholarly activity variables. Overall, the findings revealed that foreign born and non-citizens were similar in many of the variables studied and U.S. born citizens were very different than the other two citizenship groups. In spite of the belief of many researchers, the findings revealed that in many variables studied, the U.S. born Black faculty were less productive and their opinions and satisfaction differ than foreign-born and non-citizens. Also revealed in this study, but not surprising, was the fact that approximately half of Black faculty were not in a tenured track position and a very small number had tenure. The findings will assist higher education institutions in better understanding Black faculty, in addition to, assisting administrators and policymakers in providing support toward enhancing the productivity of these faculty.
Induction and Mentoring of Beginning Secondary School Teachers: A Case Study
Authors: Keengwe Jared , Adjei Boateng Emmanuel
Published: June 2012

The purpose of this study was to examine the experiences of beginning secondary school teachers in Ghana: their challenges, induction process, and the support available for them, and identify the need for a formal induction and mentoring policy for beginning teachers. Beginning secondary school teachers reported many challenges including delayed payment of salaries, problems with classroom management and assessment, and inadequate learning materials. The findings suggest that beginning teachers were not properly inducted into the teaching profession. Therefore, there is need for the government to create formal induction and mentoring policy for beginning teachers.
Effective Supervision from Research Students’ Perspective
Authors: Tahir Izah Mohd , Ghani Norizan Abdul , Atek Engku Suhaimi Engku , Manaf Zulkifli A
Published: June 2012

There are many factors that determine the success of research students in doing their postgraduate programs. Of these are the supervisors and effective supervision. The aim of this paper is to identify the attributes of supervisors and examine elements of effective supervision from the graduate research students’ perspective. In addition, the study also examines whether the means of the students’ opinions on their supervisors and effective supervision differ by demographic factors (program, faculty, course structure, gender and semester). Descriptive statistics will be used to describe the sample and Pearson chi-square test will be employed to test students’ opinions on their supervisors and effective supervision and their relationships with demographic factors. Our results suggest that the three most important attributes of supervisors are: supervisors should be friendly, approachable and flexible; knowledgeable and resourceful; and encourage students to work and plan independently. In addition, the results indicate that effective supervision means that supervisors are able to establish good and professional relationships with students; give support and guidance; and provide continuous motivation and inspiration. Using Pearson chi-square test, the results suggest that there are no significant differences in means between attributes of supervisors and effective supervision based on program, faculty, course structure, gender and semester.
Service Learning Through Mission and Ministry
Authors: Lopez Clarissa , Tsai Kuan Chen
Published: June 2012

The purpose of this study was to determine if student’s perceptions of service learning projects lead to an understanding the mission of the University of the Incarnate Word. It is through the service learning opportunity that a window opens to determine if students gain a prospective of service learning and the meaning of the mission of the institution. The research findings revealed moderate positive relationships among students’ perceptions of learning service projects and the students’ understanding of the mission of the institution. The implications and limitations of this study are discussed.
Post Choice Satisfaction among Nigerian Students Studying in Malaysian Universities: A Pilot Study
Authors: Biodun Aliyu Bukola , Haji Din Abdul Kadir , Abdullateef Aliyu Olayemi
Published: June 2012

Purpose – This research aims at developing a conceptual framework and valid prepositions of the impacts of Nigerian students’ perceived expectation on perceived quality and satisfaction with Malaysian higher institutions. The result of this study will be used for a further research that will empirically establish the actual reason for the increasing influx of Nigerian students in Malaysia and how the stakeholders can best explore the inherent opportunities. Design/methodology/approach – The researchers primarily use qualitative approach and pilot study that involves detail literature reviews of academic literatures and industry reports on perceived expectation, perceived quality and student satisfaction. Findings – The extant literatures suggest that there exist positive relationship between perceived expectation, perceived quality and student satisfaction. The reliabilities of the proposed measurement instruments indicate valid internal consistency. Research limitations/implications – Given that this paper is based on qualitative approach, there is need to embark on empirical data gathering to validate the conceptual model. Practical implications – Evidence from existing literatures have established that for higher institutions of learning to achieve operational efficiency in their perceived service quality and student satisfaction, managements of higher institutions need to integrate high quality lecturers, reasonable cost of education, social orientation programs, modern facilities etc into their operations’ measurement practices. Originality/value – This research extensively review existing literatures on student satisfaction and measurements, specifically how it impact education industry. It primarily avails both the academic and higher institution’s management the benefits that are inherent in measuring the impact of perceived expectation on perceived quality and student satisfaction. The research finally proposed a model for future empirical testing.
Lower Dietary Inclusion of Alphamune G May Improve Performance, Hematology, Serum Biochemistry and Histology of Broiler Chicken
Authors: Bolu S. A. , Adeyemi K. D. , Sola-Ojo F. E. , Fabiyi A. A. , Adedeji A. T. , Oluyemi O. , Babalola A. B.
Published: June 2012

A 56-day trial was conducted on 140 day-old broiler chicks fed graded levels of Alphamune G (0.00, 0.02, 0.03, 0.04, 0.05 and 0.06%) in a completely randomized design. Feed intake and weight gain were significantly influenced (P<0.05) by the inclusion levels of Alphamune G. Bird fed 0.00% and 0.02% Alphamune had the highest and lowest feed intake, respectively. There was no significant difference in the feed intake, weight gain and feed to gain ratio of broiler birds fed 0.04 and 0.05% Alphamune G. Birds fed Alphamune at 0.04 and 0.05% had the best feed to gain ratio. Broiler chicks fed 0.04% of Alphamune G had the highest fibre, fat and ash retention (68.70, 77.46, and 59.88%, respectively). There was no significant difference (P>0.05) in the carcass characteristics of birds fed different graded levels of Alphamune G. Haematological parameters show no significant difference among levels of Alphamune G. Serum biochemical values did not show any significant effect except for cholesterol, creatinine and uric acid. Alphamune G at 0.04% inclusion in diets may help improve performance of broiler chicken.
Patient Performed Reading of a Phototest - A Reliable Method?
Authors: L. Thorslund  , M. Falk
Published: June 2012

In various situations, in clinical practice or for prevention purposes directed at skin cancer, a broadened use of phototesting to estimate individual skin UV-sensitivity may be warranted. The aim of the present study was to investigate, in a primary health care population, the reliability of patient performed reading of a UVB phototest, when compared to the reading of a trained physician. Thirty-two subjects, all patients recruited in a primary health care population, underwent a UVB phototest, applied on the forearm. Test reading was performed after 24 hours, by the subjects themselves, by counting the number of erythemal reactions (0-6) detectable, and immediately after this, an independent control reading performed by a doctor was also done. The results showed a 72% absolute agreement between the subjects' readings and the control readings, and with a weighted kappa-value of 0.78 (95 CI: 0.64 - 0.91), i.e. corresponding to "substantial agreement". In conclusion, patient performed self-reading of a UVB phototest appears to be a fairly reliable method for estimation of individual skin UV-sensitivity, when compared to the reading of a trained observer. The finding opens up for a broadened use of phototesting in clinical practice and for preventive initiatives aiming at identifying at-risk individuals and reducing sun exposure.
The Cellient System for Cytohistology to Analyze p16 Positive Dyskeratocytes in Paraffin Sections of HPV-Positive Cervical Scrapes
Authors: Mathilde E. Boon  , Joke A.M. Dols  , Nicodemus Butamanya  , Gregor Reid
Published: June 2012

The Cellient™ Automated Cell Block System (Hologic) can be used to analyze cells of HPV-positive cervical scrapes staining positive with the biomarker p16. For this study fourteen cervical scrapes of Tanzanian women infected with HIV testing positive for HPV were selected. The paraffin Cellient sections were stained with the Papanicolaou method, with hematoxylin eosin (HE), and with the biomarker p16. This pilot study was limited to cases classified as atypical squamous lesion of unknown significance (ASCUS) and high-grade squamous lesion (HSIL) as diagnosed in the ThinPrep slide. The Cellient paraffin sections (cut from paraffin blocks prepared from the residual cervical sample) were classified into negative, atypical, CIN 1, CIN 2, and CIN 3. Multiple HPV genotypes were encountered in 79% of the scrapes. HPV16 was found in six scrapes and HPV52 in four. In the Papanicolaou sections, it was easy to detect dyskeratotic cells. Eleven of the 14 cases were p16 positive and five contained p16 positive dyskeratocytes. Of the 10 ASCUS scrapes, two contained p16 positive CIN 1 epithelial fragments. All four HSIL cases contained p16 positive CIN 3epithelial fragments. In HIV-positive HPV-positive women, the Cellient system resulted in high quality histology sections with perfect p16 images of dyskeratocytes.
Detection of Neuron Specific Enolase (NSE) with the Protein Biosensor Based on Imaging Ellipsometry
Authors: Yu Niu  , ZiyanZhao  , Gang Jin
Published: June 2012

Tumor markers can provide convincing evidence for tumor angiogenesis in early-stage, so that the need for novel and effective methods which can detect tumor markers rapidly, sensitively and reliably is consequently being subjected to extensive interest. The biosensor based on imaging ellipsometry (BIE) is developed for the detection of Neuron specific enolase (NSE) as a trial and its diagnosis performance is evaluated. Anti-NSE antibody as ligand is immobilized on protein A modified silicon substrate to form NSE sensing surface. Then, NSE test is carried out with the setup of a calibration curve for clinical quantitative detection purpose. The relationship between BIE signal y (grayscale value) and NSE concentration x (ng/ml) is y=19.6 lg(x) + 70.1 and the limit of detection achieves 2 ng/ml. The specificity, reproducibility and accuracy for NSE detection with BIE are all adequate to clinical diagnosis requirements. 149 serum samples have been detected quantitatively with BIE and their results are in agreement with a commercial ELISA immunoassay.
Precursor Lesions of Pancreatic Cancer: A Current Appraisal on Diagnosis
Authors: José Celso Ardengh  , Eder Rios de Lima-Filho  , Filadélfio Venco
Published: June 2012

The dramatic increase in the number of patients diagnosed with incidental pancreatic cysts through imaging methods provides a unique opportunity to detect and treat these precursor lesions of ductal adenocarcinoma before their manifestation. However, without any reliable biomarkers, the cost-effectiveness and the limited accuracy of high-resolution imaging techniques for diagnose and staging seems troublesome. Small pancreatic cysts can be easily detected, but many are clinically irrelevant and are not harmful to the patient. Furthermore, patients with clinically benign lesions are at high risk of overtreatment and morbidity and mortality from unnecessary surgical intervention. It is believed that cyst fluid analysis may provide important information for a possible diagnosis, allowing stratification and treatment of these patients. Anyway, only the logical reasoning based on all available information (medical history, imaging, and laboratory analysis of the aspirated cyst fluid) can adequately stratify patients. It has been considered that there are three precursor lesions of the pancreatic cancer (PC): mucinous cystadenoma (MCA), intraductal papillary mucinous tumor (IPMT) and pancreatic intraepithelial neoplasia (PanIN). MCA and IPMT can be diagnosed by imaging methods, but PanIN are difficult to be identified. They must be detected and treated as soon as possible, as this is the only way to increase survival and reduce mortality of pancreatic ductal adenocarcinoma. The aim of this work is to establish diagnosis, staging, and the pathological findings and to compare the effectiveness and accuracy of the other imaging methods versus endoscopic ultrasound guided fine-needle aspiration (EUS-FNA) for diagnosis of malignancy in the precursor lesions of pancreatic cancer.
Distinct Pattern of Inflammatory Enzyme Activities in Human Ovarian Cancer and Benign Myoma
Authors: Agnaldo L. Silva-Filho  , Andrezza V. Belo  , Elisa Lopes Lages  , Rívia Mara Lamaita  , Márcia Mendonça Carneiro  , Sílvia P. Andrade
Published: June 2012

Objective: Inflammatory cells and their products are significant components of malignancies. This study was performed to determine the activity of inflammatory enzymes myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) in ascitic fluid, sera or peritoneal lavage fluid from patients with epithelial ovarian cancer (EOC). Methods: Eighteen patients age ranging from 25 to 79 years (54.6±2.9 years) with epithelial ovarian cancer submitted to surgical treatment (EOC group) and 17 patients with uterine myoma (Myoma group) submitted to abdominal hysterectomy (control group) were prospectively studied. MPO and NAG activities were evaluated colorimetrically in sera, ascites or peritoneal lavage fluid obtained from the patients at the time of laparotomy. Results: In a total of 18 EOC, there were stage I in 1 case (5.5%), II in 3 (16.7%), III in 11 (61.1%) and IV in 3 cases (16.7%). MPO activity in sera of EOC was higher than in the ascitic fluid from the same patients. Conversely, MPO activity was similar in sera from both EOC and myoma-bearing patients. Comparison between NAG activities in sera from both groups showed much higher values in the OEC patients. Furthermore, inflammatory enzyme activities were overall associated with the stage of the disease. Conclusions: Our results show that inflammation has been positively correlated with cancer and that the pattern of a systemic inflammatory response induced by EOC differs quantitatively from that of a typical benign pelvic condition. The most important limitation lies in the fact that the number of patients and controls was relatively small. Further studies with a larger number of patients and longer follow-up are necessary to assess the accuracy of the diagnostic and prognostic impact of these results.
Proton Magnetic Resonance Spectroscopy of Sputum for the Non-Invasive Diagnosis of Lung Cancer: Preliminary Findings
Authors: Tedros Bezabeh  , Omkar B. Ijare  , E. Celia Marginean  , Garth Nicholas
Published: June 2012

Aims and Background: Sputum has been examined for the identification of potential biomarkers for the non-invasive diagnosis of lung cancer. However, no definitive biomarkers with reliable accuracy have been identified yet. The main objective of this work was to evaluate the utility of magnetic resonance spectroscopy (MRS) in the analysis of sputum for the non-invasive diagnosis of lung cancer. Methods: Induced sputum samples from lung cancer patients (n = 9) and control subjects (n = 6) were collected for proton (1H) MRS analysis. Samples from two cancer patients and one control subject were discarded as these samples were confirmed to contain only saliva by cytologic examination. Only the true sputum specimens containing alveolar macrophages were analyzed by 1H MRS. To facilitate MRS analysis, sputum samples were dispersed in 2M sodium chloride solution buffered with phosphate-buffered-saline (PBS). MR spectra were obtained using a one-pulse sequence with presaturation of the water resonance. Results: Glucose was found to be absent in sputum samples obtained from lung cancer patients. Spectra of sputum samples collected from control subjects showed presence of glucose signal except for one whose sputum cytology indicated the presence of atypia. The absence of glucose in sputum from cancer patients could be attributed to an increased rate of glycolysis in the lung cancer cells. The present observation, albeit on a small sample size, showed a better sensitivity (100%) and overall accuracy (92%) compared to sputum cytology (sensitivity = 50%; overall accuracy = 70%). Conclusions: Absence of glucose in sputum could be an indicator of lung cancer and the present methodology can be a valuable addition to the non-invasive diagnostics of lung cancer.
Ultrasound Diagnostics in Patients with Endometrial Carcinoma
Authors: Petric Aleksandra  , Stojanov Dragan  , Lilic Vekoslav  , Zivadinovic Radomir  , Lilic Goran
Published: June 2012

Introduction: Endometrial carcinoma is diagnosed by histopathological assessment of the sampled endometrium. After establishing the diagnosis the patient needs to be further evaluated in order to establish an optimal treatment. The most important factors that determine the treatment plan include: age, reproduction status, the depth of myometrial invasion, cervical invasion, histopahological type of tumor, histological and nuclear grade. Surgery is the most common treatment. The choice of optimal surgical procedure may include various imaging methods. Aim of the study: Testing the usefulness of applying the ultrasound diagnostics in preoperative evaluation of patients diagnosed with endometrial carcinoma. Method: The prospective study included 61 patients diagnosed with endometrial carcinoma. The ultrasound was used to estimate the presence and depth of invasion of the uterine muscle and cervical inclusion. The obtained parameters were compared to histopathological findings from surgically removed uterus. Results: The sensitivity of the ultrasound method in the estimation of myometrial invasion in the tested sample was 77.59%, specificity was 100.00%, predictive value of the positive test was 79.03%. The sensitivity of the ultrasound method in the estimation of cervical invasion in the tested sample was only 11.11%, specificity was 90.91%, predictive value of the positive test was 33.33%, predictive value of the negative test was 71.43%, whereas total accuracy of the method was 67.74%. Conclusion: Ultrasound diagnostics can be used in the assessment of the depth myometrial invasion but not in the assessment of cervical inclusion.
Immunohistochemical Study of CD68 and CR3/43 in Astrocytic Gliomas
Authors: Mariella Caffo  , Gerardo Caruso  , Valeria Barresi  , Maria Angela Pino  , Mario Venza  , Concetta Alafaci  , Francesco Tomasello
Published: June 2012

Diffuse and high-grade astrocytomas are invasive neoplasms which grow diffusely into the brain parenchyma. Microglia has been termed the brain's immune system, although its specific role remains uncertain. Objective of this study was to assess in a series of astrocytic neoplasms, the expression of a macrophage marker CD 68 and Major Histocompatibility Complex Class II CR3/43. We examined 10 pilocytic astrocytomas, 13 diffuse astrocytomas and 17 anaplastic astrocytomas. For macrophages we used the CD68 monoclonal mouse antibody. For assessing the presence of MHC Class II complexes we used the specific monoclonal antibody CR3/43. CD68-positive mononuclear cells were observed in perivascular and hypoxic areas, within neoplastic tissue, inside and contiguous to vessel wall. CR3/43 positive complexes were detected in mononuclear elongated elements with amoeboid extensions strictly attached to endothelial cells, or contiguous to perinecrotic areas within neoplastic tissue. We suggest an active involvement of macrophage/microglia infiltrates in neovascularization and malignancy in astrocytomas. Macrophage infiltration and major histocompatibility complex class II complexes reactivity in gliomas could also suggest the occurrence of immune surveillance with a preliminary host's immune response. In addition, macrophages could promote angiogenesis mechanisms and induction of tumor growth.
Approaches to Studying Arf GAPs in Cells: In Vitro Assay with Isolated Focal Adhesions
Authors: Chen Pei‐Wen , Jian Xiaoying , Luo Ruibai , Randazzo Paul A.
Published: June 2012

The Arf GAPs are a family of proteins with a common catalytic function of hydrolyzing GTP bound to ADP‐ribosylation factors (Arf) with proposed cellular functions that are diverse (Inoue and Randazzo, 2007; Kahn et al., 2008). Understanding the biochemistry of the Arf GAPs is valuable for designing and interpreting experiments using standard cell biology techniques described elsewhere. The following briefly reviews some common approaches for in vivo studies of Arf GAPs and discusses the use of isolated cellular organelles to complement in vivo experiments. Detailed protocols for examining the activity of Arf GAPs in whole cell lysates and in association with isolated focal adhesions are provided. Curr. Protoc. Cell Biol. 55:17.13.1‐17.13.20. © 2012 by John Wiley & Sons, Inc.
Cardiac Differentiation of Human Embryonic Stem Cells and their Assembly into Engineered Heart Muscle
Authors: Soong Poh Loong , Tiburcy Malte , Zimmermann Wolfram‐Hubertus
Published: June 2012

The advent of pluripotent human embryonic stem cells has created the unique opportunity for the development of a wide variety of humanized cellular tools for basic research, as well as industrial and clinical applications. It has, however, become apparent that embryonic stem cell derivatives in classical monolayer or embryoid body culture do not resemble bona fide tissues, mainly because of their limited organotypic organization and maturation in these culture formats. This shortcoming may be addressed by tissue engineering technologies aiming at the provision of a “natural” growth environment to facilitate organotypic tissue assembly. In this unit, we provide two harmonized basic protocols for (1) cardiac differentiation of human embryonic stem cells under serum‐free conditions and (2) the assembly of the stem cell–derived cardiomyocytes into engineered heart muscle. This protocol can be easily adapted to bioengineer heart muscle also from other stem cell–derived cardiomyocytes, including cardiomyocytes from human‐induced pluripotent stem cells. Curr. Protoc. Cell Biol. 55:23.8.1‐23.8.21. © 2012 by John Wiley & Sons, Inc.
A Constrained Model for MSMA
Authors: Capella Antonio , Müller Stefan , Otto Felix
Published: June 2012

A mathematical description of transformation processes in magnetic shape memory alloys (MSMA) under applied stresses and external magnetic fields needs a combination of micromagnetics and continuum elasticity theory. In this note, we discuss the so‐called constrained theories, i.e., models where the state described by the pair (linear strain, magnetization) is at every point of the sample constrained to assume one of only finitely many values (that reflect the material symmetries). Furthermore, we focus on large body limits, i.e., models that are formulated in terms of (local) averages of a microstructured state, as the one proposed by DeSimone and James. We argue that the effect of an interfacial energy associated with the twin boundaries survives on the level of the large body limit in form of a (local) rigidity of twins. This leads to an alternative (i.e., with respect to reference1) large body limit. The new model has the advantage of qualitatively explaining the occurrence of a microstructure with charged magnetic walls, as observed in SPP experiments in reference2.
Dynamic Processes in Sandwich Polymer Light‐Emitting Electrochemical Cells
Authors: van Reenen Stephan , Janssen René A. J. , Kemerink Martijn
Published: June 2012

The operational mechanism of polymer light‐emitting electrochemical cells (LECs) in sandwich geometry is studied by admittance spectroscopy in combination with numerical modeling. At bias voltages below the bandgap of the semiconducting polymer, this allows the determination of the dielectric constant of the active layer, the conductivity of mobile ions, and the thickness of the electric double layers. At bias voltages above the bandgap, p–n junction formation gives rise to an increase in capacitance at intermediate frequencies (≈10 kHz). The time and voltage dependence of this junction are successfully studied and modeled. It is shown that impedance measurements cannot be used to determine the junction width. Instead, the capacitance at intermediate biases corresponds to a low‐conductivity region that can be significantly wider than the recombination zone. Finally, the long settling time of sandwich polymer LECs is shown to be due to a slow process of dissociation of salt molecules that continues after the light‐emitting p–n junction has formed. This implies that in order to significantly decrease the response‐time of LECs an electrolyte/salt combination with a minimal ion binding energy must be used.
Elaborately Aligning Bead‐Shaped Nanowire Arrays Generated by a Superhydrophobic Micropillar Guiding Strategy
Authors: Wu Yuchen , Chen Xiao , Su Bin , Song Yanlin , Jiang Lei
Published: June 2012

Bead‐shaped 1D structures are of great interest due to their unique applications in mesoscopic optics/electronics and their specific ability to collect tiny droplets. Here, a novel method to fabricate aligning bead‐shaped nanowire arrays assisted by highly adhesive superhydrophobic surfaces based on a micropillar guiding strategy is presented. Different from previous fabrication techniques, bead‐shaped nanowires generated in this method are strictly oriented in a large scale. Rayleigh instability, which occurs at ultralow polymer concentration, can introduce bead‐shaped nanowires at the cost of structural strength. Thus, PS spheres are more suitable to serve as bead building blocks to generate firm bead‐shaped nanowire arrays. The bead number is tunable by tailoring the polystyrene‐sphere/polyvinyl‐formal ratio. Furthermore, as‐prepared bead‐shaped nanowires have the unique ability to directionally drive tiny drops and collect coalesced microdroplets when placed in mist. With an increase in humidity, the nanowires show a segmented swelling behavior in the “bead” parts whereas the “joint nanowire” parts remain the same. Because such bead‐shaped nanowires are formed regularly, collected microdroplets upon the beads would not interact with each other. The findings offer new insight into the alignment of bead‐shaped nanostructures and might provide promising opportunities in fundamental research and for industrial applications.
Enhancement of Proton Conduction at Low Humidity by Incorporating Imidazole Microcapsules into Polymer Electrolyte Membranes
Authors: Wang Jingtao , Yue Xiujun , Zhang Zizhuo , Yang Zheng , Li Yifan , Zhang Han , Yang Xinlin , Wu Hong , Jiang Zhongyi
Published: June 2012

Design and fabrication of hierarchically structured membranes with high proton conductivity is crucial to many energy‐relevant applications including proton exchange membrane fuel cell (PEMFC). Here, a series of imidazole microcapsules (IMCs) with tunable imidazole group loading, shell thickness, and lumen size are synthesized and incorporated into a sulfonated poly(ether ether ketone) (SPEEK) matrix to prepare composite membranes. The IMCs play two roles: i) Improving water retention properties of the membrane. The IMCs, similar to the vacuoles in plant cells, can render membrane a stable water environment. The lumen of the IMCs acts as a water reservoir and the shell of IMCs can manipulate water release. ii) They form anhydrous proton transfer pathways and low energy barrier pathways for proton hopping, imparting an enhanced proton transfer via either a vehicle mechanism or Grotthuss mechanism. In particular, at the relative humidity (RH) as low as 20%, the composite membrane exhibits an ultralow proton conductivity decline and the proton conductivity is one to two orders of magnitude higher than that of SPEEK control membrane. The enhanced proton conductivity affords the composite membrane an elevated peak power density from 69.5 to 104.5 mW cm−2 in a single cell. Moreover, the application potential of the composite membrane for CO2 capture is explored.
Magnetic resonance imaging pattern in natalizumab‐associated progressive multifocal leukoencephalopathy
Authors: Yousry Tarek A. , Pelletier Daniel , Cadavid Diego , Gass Achim , Richert Nancy D. , Radue Ernst‐Wilhelm , Filippi Massimo
Published: June 2012

Objective:

Natalizumab is an effective treatment for patients with multiple sclerosis (MS) that is associated with a risk of progressive multifocal leukoencephalopathy (PML). Recommendations were published in 2006 to improve early diagnosis of PML using magnetic resonance imaging (MRI). However, due to the small number of MS patients initially diagnosed with PML, the imaging criteria could only be derived from PML lesions in patients with human immunodeficiency virus. Therefore, there is an urgent need to assess the MRI characteristics of PML in MS patients to update the existing recommendations.

Methods:

In this retrospective review, the first 40 natalizumab‐treated MS patients diagnosed with PML in the postmarketing setting were identified, of whom 22 (10 with clinically diagnosed immune reconstitution inflammatory syndrome) fulfilled the inclusion criteria for this study. Magnetic resonance images were analyzed according to predefined criteria by 5 independent readers.

Results:

The most frequent lesion pattern in early scans from PML patients was that of large (>3 cm, 15 of 18), subcortical (18 of 18), T2 or fluid‐attenuated inversion recovery hyperintense (18 of 18), T1‐hypointense (17 of 18), and diffusion‐hyperintense (15 of 15) lesions, with a sharp border toward the gray matter and an ill‐defined border toward the white matter (18 of 18) on T2‐weighted images. We could detect contrast enhancement in 41% (7 of 17) of the cases on the first scan at clinical presentation.

Interpretation:

Attention to characteristic MRI patterns, especially the presence of contrast enhancement, and the subcortical location may have utility in screening and early diagnosis of PML in natalizumab‐treated MS patients. ANN NEUROL 2012;72:779–787
Hemorrhagic transformation of ischemic stroke in diabetics on sulfonylureas
Authors: Kunte Hagen , Busch Markus A. , Trostdorf Katrin , Vollnberg Bernd , Harms Lutz , Mehta Rupal I. , Castellani Rudolf J. , Mandava Pitchaiah , Kent Thomas A. , Simard J. Marc
Published: June 2012

Objective:

Disability or death occurs more frequently in patients with hemorrhagic transformation (HT) after ischemic stroke. In rat models of stroke, sulfonylurea (SU) drugs such as glibenclamide (adopted US name, glyburide) confer protection against swelling and HT through actions on the novel SUR1‐regulated NCCa‐ATP channel. Here, we sought to determine whether the use of SU drugs in patients with diabetes mellitus (DM) presenting with acute ischemic stroke might influence the incidence of HT.

Methods:

We retrospectively analyzed data on 220 patients with DM who presented with acute ischemic stroke, 43 of whom were managed with and continued to receive SU drugs, and 177 of whom were managed without (controls).

Results:

During a median length of stay in hospital of 11 days, 20 control patients (11%) experienced symptomatic HT (sHT), whereas no patient in the SU group experienced sHT (p = 0.016). No patient in the SU group died, compared to 18 (10%) in the control group (p = 0.027). Similarly favorable outcomes were observed after matching for baseline imbalances and excluding outliers. In support of the proposed mechanism, we present a case of sHT in which an analysis of brain tissues obtained intraoperatively showed prominent upregulation of SUR1, the target of SU drugs, in microvessels and neurons.

Interpretation:

We conclude that, in diabetic patients with acute ischemic stroke, prior and continued use of SU drugs is associated with reduced sHT compared to those whose treatment regimen does not include SU drugs. ANN NEUROL 2012;72:799–806
Crosslinking reaction and properties of two‐component waterborne polyurethane from terpene‐maleic ester type epoxy resin
Authors: Wu Guo‐min , Kong Zhen‐wu , Chen Cai‐feng , Chen Jian , Huo Shu‐ping , Jiang Jian‐chun
Published: June 2012

A two‐component waterborne polyurethane (2K‐WPU) is prepared with the terpene‐maleic ester type epoxy resin‐based polyol dispersion and a hydrophilically modified hexamethylene diisocyanate tripolymer. Laser particle size analyzer and transmission electron microscopy are used to characterize the particle size distribution and the micromorphology of the 2K‐WPU. Crosslinking reaction kinetics of the 2K‐WPU is examined by fourier transform infrared spectrometry (FTIR) spectra. In the preliminary stage of the crosslinking reaction, it shows a very good fit with a second order reaction kinetics, and the apparent activation energy is 94.61 kJ mol−1. It is also shown from the FTIR spectra that the complete crosslinking reaction of the 2K‐WPU needs 7 h at 70°C. The crosslinked products of the 2K‐WPU have good thermal resistant properties, with glass‐transition temperatures (Tg) in the range of 35–40°C and 10% weight loss temperatures (Td) in the range of 275–287°C. The films obtained from the crosslinked products have good water‐resistance, antifouling, blocking resistance properties and impact strength of >50 cm, flexibility of 0.5 mm, adhesion of 1 grade, pencil hardness of HB‐2H. The pencil hardness and thermal‐resistant properties of the crosslinked products increase with the molar ratio of isocyanate (NCO) group to hydroxyl (OH) group. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013