bluuebunny/crossref_metadata_2025_split huggingface dataset:
Generalized geoidal estimators for deterministic modifications of spherical Stokes' function
Authors: Šprlák Michal 
Published: June 2010

Generalized geoidal estimators for deterministic modifications of spherical Stokes' functionStokes' integral, representing a surface integral from the product of terrestrial gravity data and spherical Stokes' function, is the theoretical basis for the modelling of the local geoid. For the practical determination of the local geoid, due to restricted knowledge and availability of terrestrial gravity data, this has to be combined with the global gravity model. In addition, the maximum degree and order of spherical harmonic coefficients in the global gravity model is finite. Therefore, modifications of spherical Stokes' function are used to obtain faster convergence of the spherical harmonic expansion. Decomposition of Stokes' integral and modifications of Stokes' function have been studied by many geodesists. In this paper, the proposed deterministic modifications of spherical Stokes' function are generalized. Moreover, generalized geoidal estimators, when the Stokes' integral is decomposed in to spectral and frequency domains, are introduced. Higher derivatives of spherical Stokes' function and their numerical stability are discussed. Filtering and convergence properties for deterministic modifications of the spherical Stokes' function in the form of a remainder of the Taylor polynomial are studied as well.
Improving accuracy and reducing radiation exposure in minimally invasive lumbar interbody fusion
Authors: Wood Martin James , Mannion Richard John 
Published: June 2010

Object
The authors assessed the accuracy of placement of lumbar transpedicular screws by using a computer-assisted, imaged-guided, minimally invasive technique with continuous electromyography (EMG) monitoring.

Methods
This was a consecutive case series with prospective assessment of procedural accuracy. Forty-seven consecutive patients underwent minimally invasive lumbar interbody fusion and placement of pedicle screws (PSs). A computer-assisted image guidance system involving CT-based images was used to guide screw placement, while EMG continuously monitored the lumbar nerve roots at the operated levels with a 5-mA stimulus applied through the pedicle access needle. All patients underwent CT scanning to determine accuracy of PS placement. All episodes of adjusted screw trajectory based on positive EMG responses were recorded. Pedicle screw misplacement was defined as breach of the pedicle cortex by the screw of more than 2 mm.

Results
Two hundred twelve PSs were inserted in 47 patients. The screw misplacement rate was 4.7%. One patient experienced new postoperative radiculopathy resulting from a sacral screw that was too long, with lumbosacral trunk impingement. The trajectory of the pedicle access needle was altered intraoperatively on 20 occasions (9.4% of the PSs) based on positive EMG responses, suggesting that nerve root impingement may have resulted from these screws had the EMG monitoring not been used.

Conclusions
The combination of computer-assisted navigation combined with continuous EMG monitoring during pedicle cannulation results in a low rate of PS misplacement, with avoidance of screw positions that might cause neural injury. Furthermore, this technique allows reduction of the radiation exposure for the surgical team without compromising the accuracy of screw placement.
Risk factors for surgical site infection following spine surgery: efficacy of intraoperative saline irrigation
Authors: Watanabe Masahiko , Sakai Daisuke , Matsuyama Daisuke , Yamamoto Yukihiro , Sato Masato , Mochida Joji 
Published: June 2010

ObjectThe purpose of this study was to identify risk factors for surgical site infection after spine surgery, noting the amount of saline used for intraoperative irrigation to minimize wound contamination.MethodsThe authors studied 223 consecutive spine operations from January 2006 through December 2006 at our institute. For a case to meet inclusion criteria as a site infection, it needed to require surgical incision and drainage and show positive intraoperative cultures. Preoperative and intraoperative data regarding each patient were collected. Patient characteristics recorded included age, sex, and body mass index (BMI). Preoperative risk factors included preoperative hospital stay, history of smoking, presence of diabetes, and an operation for a traumatized spine. Intraoperative factors that might have been risk factors for infection were collected and analyzed; these included type of procedure, estimated blood loss, duration of operation, and mean amount of saline used for irrigation per hour. Data were subjected to univariate and multivariate logistic regression analyses.ResultsThe incidence of surgical site infection in this population was 6.3%. According to the univariate analysis, there was a significant difference in the mean duration of operation and intraoperative blood loss, but not in patient age, BMI, or preoperative hospital stay. The mean amount of saline used for irrigation in the infected group was less than in the noninfected group, but was not significantly different. In the multivariate analysis, sex, advanced age (> 60 years), smoking history, and obesity (BMI > 25 kg/m2) did not show significant differences. In the analysis of patient characteristics, only diabetes (patients receiving any medications or insulin therapy at the time of surgery) was independently associated with an increased risk of surgical site infection (OR 4.88). In the comparison of trauma and elective surgery, trauma showed a significant association with surgical site infection (OR 9.42). In the analysis of surgical factors, a sufficient amount of saline for irrigation (mean > 2000 ml/hour) showed a strong association with the prevention of surgical site infection (OR 0.08), but prolonged operation time (> 3 hours), high blood loss (> 300 g), and instrumentation were not associated with surgical site infection.ConclusionsDiabetes, trauma, and insufficient intraoperative irrigation of the surgical wound were independent and direct risk factors for surgical site infection following spine surgery. To prevent surgical site infection in spine surgery, it is important to control the perioperative serum glucose levels in patients with diabetes, avoid any delay of surgery in patients with trauma, and decrease intraoperative contamination by irrigating > 2000 ml/hour of saline in all patients.
Quantitative analysis of misplaced pedicle screws in the thoracic spine: how much pullout strength is lost?
Authors: Brasiliense Leonardo B. C. , Theodore Nicholas , Lazaro Bruno C. R. , Sayed Zafar A. , Deniz Fatih Ersay , Sonntag Volker K. H. , Crawford Neil R. 
Published: June 2010

ObjectThe object of this study was to investigate the effects of iatrogenic pedicle perforations from screw misplacement on the mean pullout strength of thoracic pedicle screws.MethodsForty human thoracic vertebrae (T6–11) from human cadavers were studied. Before pedicle screws were inserted, the specimens were separated into 4 groups according to the type of screw used: 1) standard pedicle screw (no cortical perforation); 2) screw with medial cortical perforation; 3) screw with lateral cortical perforation; and 4) “airball” screw (a screw that completely missed the vertebral body). Consistency among the groups for bone mineral density, pedicle diameter, and screw insertion depth was evaluated. Finally, each screw was pulled out at a constant displacement rate of 10 mm/minute while ultimate strength was recorded.ResultsCompared with well-placed pedicle screws, medially misplaced screws had 8% greater mean pullout strength (p = 0.482) and laterally misplaced screws had 21% less mean pullout strength (p = 0.059). The difference in mean pullout strength between screws with medial and lateral cortical perforations was significant (p = 0.013). Airball screws had only 66% of the mean pullout strength of well-placed screws (p = 0.009) and had 16% lower mean pullout strength than laterally misplaced screws (p = 0.395).ConclusionsThis in vitro study showed a significant difference in mean pullout strength between medial and lateral misplaced pedicle screws. Moreover, airball screws were associated with a significant loss of pullout strength.
Morbidity and mortality in the surgical treatment of 10,329 adults with degenerative lumbar stenosis
Authors: Fu Kai-Ming G. , Smith Justin S. , Polly David W. , Perra Joseph H. , Sansur Charles A. , Berven Sigurd H. , Broadstone Paul A. , Choma Theodore J. , Goytan Michael J. , Noordeen Hilali H. , Knapp D. Raymond , Hart Robert A. , Zeller Reinhard D. , Donaldson William F. , Boachie-Adjei Oheneba , Shaffrey Christopher I. 
Published: June 2010

Object
The purpose of this study was to evaluate the prospectively collected Scoliosis Research Society (SRS) database to assess the incidences of morbidity and mortality (M&M) in the operative treatment of degenerative lumbar stenosis, one of the most common procedures performed by spine surgeons.

Methods
All patients who underwent surgical treatment for degenerative lumbar stenosis between 2004 and 2007 were identified from the SRS M&M database. Inclusion criteria for analysis included an age ≥ 21 years and no history of lumbar surgery. Patients were treated with either decompression alone or decompression with concomitant fusion. Statistical comparisons were performed using a 2-sided Fisher exact test.

Results
Of the 10,329 patients who met the inclusion criteria, 6609 (64%) were treated with decompression alone, and 3720 (36%) were treated with decompression and fusion. Among those who underwent fusion, instrumentation was placed in 3377 (91%). The overall mean patient age was 63 ± 13 years (range 21–96 years). Seven hundred nineteen complications (7.0%), including 13 deaths (0.1%), were identified. New neurological deficits were reported in 0.6% of patients. Deaths were related to cardiac (4 cases), respiratory (5 cases), pulmonary embolus (2 cases), and sepsis (1 case) etiologies, and a perforated gastric ulcer (1 case). Complication rates did not differ based on patient age or whether fusion was performed. Minimally invasive procedures were associated with fewer complications and fewer new neurological deficits (p = 0.01 and 0.03, respectively).

Conclusions
The results from this analysis of the SRS M&M database provide surgeons with useful information for preoperative counseling of patients contemplating surgical intervention for symptomatic degenerative lumbar stenosis.
Neurological manifestations, imaging characteristics, and surgical outcome of intraspinal osteochondroma
Authors: Lotfinia Iraj , Vahedi Payman , Tubbs R. Shane , Ghavame Mostafa , Meshkini Ali 
Published: June 2010

ObjectSpinal osteochondromas (OCs) are rare and can originate as solitary lesions or in the context of hereditary multiple exostoses. Concurrent spinal cord compression is a very rare entity. The purpose of this study was to evaluate the authors' 10-year experience with the imaging characteristics and surgical outcome in patients with symptomatic spinal OC.MethodsBetween 1997 and 2007, 8 consecutive cases of symptomatic intraspinal OC with documented spinal cord compression were treated surgically. These patients were analyzed with regard to presentation, imaging, and outcome. The relevant English literature was reviewed using MEDLINE and Google search engines.ResultsThree patients had cervical, 2 had thoracic, and 3 had lumbar lesions. Classic MR imaging characteristics were rarely found. Multiple hereditary exostoses were equally responsible for cervical, thoracic, and lumbar lesions (33%). The origin of the lesion was from the pedicle (25%), lamina (25%), vertebral body (25%), and superior or inferior facets (25%). A posterior approach to the spine was used in 6 patients, and a combined anterior and posterior approach with fusion was performed for 2 thoracic lesions. Surgical outcome was satisfactory in 75% of patients. The prognosis was poor in the patients with thoracic lesions.ConclusionsIn the authors' experience, early detection and surgical removal in cases of symptomatic spinal OC is a key element for the best outcome. Posterior approaches are generally sufficient. The chronicity of symptoms may limit functional recovery postoperatively, especially with cervical and thoracic lesions.
Childhood cancers in a referral hospital in northern Nigeria
Authors: Mohammed A , Aliyu H O 
Published: June 2010

Abstract
Background:We undertook this study to determine the relative frequencies of childhood malignancies and their age - sex distribution in this environment.Materials and Methods:Hospital-based data of histological and cytologically confirmed cases of malignancies in children, aged ≤ 15 years, was collated over a period of 11 years, from the Cancer Registry.Results:A total of 329 children aged ≤ 15 years, with confirmed malignant disease, was recorded. This constituted 8.44% of all malignancies diagnosed in the same period with a Male : Female ratio of 1.5:1. Burkitt′s lymphoma accounted for 27.01% of the cases followed by retinoblastoma (17.02%), non-Hodgkin′s non-Burkitt′s Lymphoma (9.42%), and Rhabdomyosarcoma (9.42%). Others were Nephroblastoma (8.81%), Hodgkin′s lymphoma (6.69%), Neuroblastoma (3.34%), Colorectal carcinoma (2.43%), Osteosarcoma (2.13%), and Unspecified lymphomas (1.82%). Burkitt′s lymphoma was most prevalent in the 5-9 and 10-15 year age groups, retinoblastoma in the 0-4 year age group, and Non-Hodgkin′s lymphoma, Hodgkin′s lymphoma, and unspecified carcinomas were more prevalent in the 10-15 year age group.Conclusion:Lymphomas were the most prevalent malignancies of childhood seen in this region and the majority were of the Burkitt type, in contrast to the predominant leukemic and central nervous system trend seen in developed nations.
Expression of human chorionic gonadotropin beta in gastric carcinoma: A retrospective immunohistochemical study
Authors: Murhekar Kanchan M , Anuratha Jayaram N , Majhi Urmila , Rajkumar Thangarajan 
Published: June 2010

Abstract
Context:Beta Human Chorionic Gonadotropin (βHCG), a marker of the trophoblastic neoplasm, is also secreted by non-trophoblastic neoplasms including gastric carcinomas. Its role in disease progression remains unclear.Aim:To investigate the incidence of βHCG positivity in gastric carcinomas and correlate its presence with the biological behavior of the tumor.Setting and Design:A hospital-based, immunohistochemical study.Materials and Methods:One hundred and fifty formalin-fixed, paraffin-embedded tissue specimens from histopathologically confirmed cases of gastric carcinoma were immunostained using an indigenously developed antibody against βHCG. Tumors with diffuse reactivity to βHCG were considered as positive. Those with occasional, focal or no reactivity to βHCG were considered as negative.Statistical Analysis:Differences in βHCG staining were compared according to the histological grade and surgical stage using the χ2test. Using the Cox proportional hazards model, the time till the onset of development of an adverse outcome after surgery (defined as death, local or distant metastasis) was compared between the bHCG positive and negative tumors.Results:Twenty-eight (18.7%) of the 150 specimens were βHCG positive. No association was found between the histological grade (P=0.49) and the surgical stage (P=0.19) with βHCG positivity. The median disease-free survival after surgery was not different among bHCG positive and negative tumors. Risk of an adverse outcome after surgery was significantly associated with the stage of the tumor (Hazard ratio=2.9, 95% confidence interval: 1.1-7.4). No association was observed with grade or βHCG positivity.Conclusion:βHCG immunoreactivity was observed in about one-fifth of the gastric cancers. bHCG reactivity, however, played no role in the biological behavior.
Persistent hypokalemia in an acute lymphoblastic leukemia patient
Authors: Ali Altaf , Aziz Sheikh Ajaz , Khan Afaq , Gelani Sajad 
Published: June 2010

AbstractNephrotoxicity is an important adverse effect of Amphotericin B, and although risk factors for nephrotoxicity in adults have been investigated, studies examining nephrotoxicity in the pediatric population are scarce. We describe case of 10 year old boy (CALLA - VE B cell ALL) who received conventional Amphotericin-B, but he persisted with hypokalemia.
Ganglioneuroma of the retroperitoneum presenting as a pediatric renal mass
Authors: Cyriac Sanju , Srinivas Lakshmi , Kathiresan N , Sundersingh Shirley , Mahajan Vandana , Sagar T.G. 
Published: June 2010

AbstractGanglioneuroma is the benign representative of peripheral neuroblastic tumors, with localized and predominant thoracic presentations in older children. They often have an excellent outcome with surgery alone. A 12-year-old girl presented with an incidentally detected abdominal mass, which was clinicoradiologically a renal mass. Laparotomy revealed a mass adherent to the anterior surface of the right kidney. The mass was carefully dissected out, sacrificing a portion of the inferior vena cava. Histopathological diagnosis was that of a ganglioneuroma. She was kept under follow up.
Follicular mycosis fungoides - A report of four Indian cases
Authors: Rajalakshmi T , Inchara Y.K. , Antony Meryl 
Published: June 2010

Abstract
Background:Follicular Mycosis Fungoides (FMF) is an under-recognized disease in India. Its clinical mimics include Hansen′s disease and Sarcoidosis.Aims:To describe the clinical and pathological features of FMF.Materials and Methods:All cases of FMF between January and December 2007 were retrieved. Cases of conventional epidermotropic MF with a minor follicular component were excluded. Slides were reviewed by two observers. The following criteria were assessed: degree and density of folliculotropism of lymphocytes, location of folliculotropism (infundibular / isthmic / bulbar), follicular mucin, eosinophils, granulomas, and conventional epidermotropism. Each feature was assigned a semi-quantitative grade.Results:There were four cases of FMF, with an equal gender distribution and a mean age of 17.5 years. All lesions were on the face. They presented as: hypopigmented patches (2) and erythematous plaques (2). Alopecia was seen in two cases. The clinical diagnosis was Hansen′s disease in all four, with a differential of Alopecia mucinosa / Sarcoidosis in two cases.The histological features seen were: disproportionate folliculotropism, lymphocyte tagging with haloes, follicular mucin, and nucleomegaly / convolution in all four cases, prominent eosinophils (2), epithelioid granulomas (1), eccrine infiltration (4), parakeratosis at the follicular ostia (2), and sebaceotropism (1). The infiltrate was bulbar (4) and isthmic (2). The rest of the epidermis showed no hint of conventional MF.Conclusion:The preferential features for FMF were involvement of face, dominant folliculotropism, nuclear atypia and convolution, and follicular mucin. Presence of granulomas and eosinophils necessitated exclusion of infectious causes. The absence of findings of MF in the rest of the epidermis should not deter pathologists from rendering this diagnosis.
Uterine C-Kit positive low grade stromal sarcoma
Authors: Martin Jovitha , Ramesh Anita , Kuruvilla Sarah , Lalitha D 
Published: June 2010

AbstractUterine C-Kit positive stromal tumors are rare, however, there are a few cases reported in literature. A 58-year-old post menopausal lady presented with bleeding per vaginum. An abdominal examination revealed an enlarged uterus. A computed tomography scan of the abdomen and pelvis showed a large myomatous uterus, with a probable subserosal intramural and intracavitary myoma or cervical myoma in the presence of a solitary large aortocaval node, with multiple bone lesions. The biopsy taken from the uterine mass had revealed, a low-grade uterine sarcoma, which was positive for CD117. This case is presented for its rarity and management dilemma.
Basics of Statistical Analysis
Authors: Thomson Diane M. 
Published: June 2010

AbstractThe goal of this appendix is to introduce basic methods in graphing and data analysis and explore some fundamental concepts in statistical reasoning. Three examples of data‐analysis problems relevant to molecular biology are used to illustrate methods covered in a first statistics course, including the two‐sample t test, simple linear regression, and chi square tests for goodness of fit and contingency table hypotheses. The appendix also explores the selection and interpretation of appropriate summary graphs for these analyses, including the use of error bar plots, scatterplots, and bar charts. In addition, a number of key terms and concepts are introduced and explained in the context of the three example problems, including summary statistics, sampling variation, the standard error, null hypothesis testing, the use of test statistics, and the interpretation of p values. Curr. Protoc. Essential Lab. Tech. 3:A.4B.1‐A.4B.22. © 2010 by John Wiley & Sons, Inc.
A Societal Cost of Obesity in Terms of Automobile Fuel Consumption
Authors: Jacobson Sheldon H. , King Douglas M. 
Published: June 2010

Abstract
Growing obesity rates in the United States increase fuel consumption by adding passenger weight to vehicles, demonstrating a link between these two significant socioeconomic issues. This article quantifies several estimates for the annual amount of fuel consumed by noncommercial passenger highway vehicles (i.e., cars and light trucks) in the United States that can be attributed to passenger overweight and obesity. Using a previously published mathematical model, it is estimated that up to one billion gallons of fuel or more are consumed each year due to passenger weight that can be attributed to overweight and obesity, or up to 0.8% of the fuel consumed by cars and light trucks each year. Estimates are generated based on the increase in average weight in the US population over historical time periods, and by direct estimation of the average weight that can be attributed to overweight and obesity in the US population. From an environmental perspective, this additional fuel consumption has the effect of up to 20 billion pounds or more of carbon dioxide emissions, up to 0.5% of such emissions produced in the transportation sector.
Age Replacement Policies
Authors: Ebrahimi Nader 
Published: June 2010

AbstractMaintenance policies are followed to reduce the incidence of unit failure or to return a failed unit to the operating state. This article concentrates on a particular maintenance policy referred to as an age replacement policy. Under this policy, a unit is replaced upon failure or at a specified age whichever comes first. We develop some of its desirable properties and obtain an optimal age replacement policy. We also define a multivariate version of this policy and give its properties.
Aging, Characterization, and Stochastic Ordering
Authors: Belzunce Félix , Shaked Moshe 
Published: June 2010

Abstract

In this article, we list a number of results that characterize various aging and antiaging notions in terms of stochastic comparisons of related random variables. The random variables that are used in the comparisons are the corresponding residual lives or the corresponding asymptotic equilibrium ages. The aging notions that are studied are the increasing failure rate (IFR), the increasing failure rate average (IFRA), the new better than used (NBU), the decreasing mean residual life (DMRL), as well as other related notions; the corresponding antiaging notions are also characterized in this article. The characterizations are by means of the ordinary stochastic order ≤
st
, of the hazard rate stochastic order ≤
hr
, of the dispersive stochastic order ≤
disp
, of the location‐independent riskier stochastic order ≤
lir
, of the excess wealth stochastic order ≤
ew
, of the increasing convex and the increasing concave stochastic orders ≤
icx
and ≤
icv
, of the Laplace transform stochastic order ≤
Lt
, of the likelihood ratio stochastic order ≤
lr
, as well as by means of other related stochastic orders.