bluuebunny/crossref_metadata_2025 huggingface dataset:
Screening of N‐Alkyl‐Cyanoacetamido Oximes as Substitutes for N‐Hydroxysuccinimide
Authors: Khattab Sherine N. , Subirós‐Funosas Ramon , El‐Faham Ayman , Albericio Fernando
Published: June 2012

Peptide‐bond formation is a pivotal process in the synthesis of peptide oligomers. Among the various coupling methodologies described, carbodiimides combine strong acylation potency and smooth reaction conditions, and they are commonly used in the presence of N‐hydroxylamine additives. In recent years, acidic oxime templates, mainly ethyl 2‐cyano‐2‐(hydroxyimino) acetate (Oxyma), have emerged as highly reactive alternatives to the classic and explosive‐prone benzotriazolic additives, 1‐hydroxybenzotriazole (HOBt) and 1‐hydroxy‐7‐azabenzotriazole (HOAt). However, to achieve certain biochemical targets, less reactive species, such as N‐hydroxysuccinimide (HOSu) esters, are often required to obtain stability under aqueous conditions. In the present study, we report on a new family of water‐soluble N‐alkyl‐cyanoacetamido oximes, most of which have proven useful in the construction of active carbonates for the introduction of fluorenylmethoxycarbonyl (Fmoc) with minimal impact of dipeptide impurities. We performed a direct comparison of these new N‐alkyl‐cyanoacetamido oximes with HOSu in order to evaluate their capacity to retain optical purity and their coupling efficiency in the assembly of bulky residues.
Hepatocarcinogenesis in non‐cirrhotic liver is associated with a reduced number of clonal hepatocellular patches in non‐tumorous liver parenchyma
Authors: Adam Alexander C. , Faudou Viola , Paschen Stefan A , Adam Olaf M , Kahl Philip , Drebber Uta , Fischer Hans‐Peter , Büttner Reinhard
Published: June 2012

We investigated circumscribed cell proliferations in healthy livers in comparison to non‐cirrhotic livers bearing hepatocellular carcinoma. Using histochemical staining for cytochrome c oxidase, the fourth complex of the respiratory chain, we visualized patch‐forming descendents of regeneratively active liver cells. The clonal nature of these patches was verified by laser‐capture microdissection and Sanger sequencing of the enzyme's core subunits in patches carrying marker mutations on the mtDNA. We demonstrate a highly significant increase of the patch size and also a highly significant increase in the number of patches carrying marker mutations between hepatocellular carcinoma‐free and ‐bearing livers. Thus, the carcinoma‐bearing livers accumulated more genetic damage on mtDNA than the control group. Furthermore, for the first time, we present evidence in hepatocellular carcinoma‐bearing non‐cirrhotic livers of a significantly reduced pool of regeneratively active liver cells that are genetically and functionally altered. The analogy to ageing‐related changes is suggestive of premature ageing of stem cells in non‐cirrhotic hepatocellular carcinoma‐bearing liver as an early step to hepatocarcinogenesis. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Rapid and effective removal of perfluorooctanoic acid from proteomics samples
Authors: Rao Kadiyala Chandra Sekhar , Mullangi Vennela , Zhou Xiang , Vukoti Krishna M. , Miyagi Masaru
Published: June 2012

We recently demonstrated that perfluorooctanoic acid (PFOA), a volatile surfactant, is as effective as sodium dodecyl sulfate at solubilizing the membrane proteins. PFOA can be removed by repeated evaporation prior to mass spectrometry analysis. However, the removal of PFOA by evaporation is a lengthy process that takes approximately 6 h. Toward the goal of decreasing the length of time required to remove PFOA from protein digests, we tested the efficiency of PFOA removal and subsequent peptide recovery using strong cation exchange (SCX) chromatography, hydrophilic interaction chromatography (HILIC), fluorous solid phase extraction (FSPE), and anion exchange (ANX) chromatography. We found that all these chromatographic techniques except ANX chromatography remove PFOA thoroughly from protein digest. Peptide recovery rates from the SCX chromatography varied widely; nonacidic peptides were recovered at a rate of up to 95%, while acidic peptides were recovered at a rate of less than 10%. On the other hand, acidic peptides were recovered well from HILIC, while peptides whose pIs are greater than 6 were recovered poorly. Peptide recovery using FSPE was considerably lower, less than 10% for most of the peptides. These results indicate that the SCX and HILIC chromatography provide a more rapid alternative to the evaporation method for applications in which recovery of entire set of peptides is not required.
Psychosocial predictors of adherence to lymphedema risk minimization guidelines among women with breast cancer
Authors: Sherman Kerry A. , Koelmeyer Louise
Published: June 2012

Background

The effective management of lymphedema risk following breast cancer surgery and treatment requires enactment of simple behavioural strategies, including regularly checking for early lymphedema symptoms. Adopting a broad self‐regulatory perspective, our aim for this study was to identify psychological factors associated with adherence to these risk management strategies.

Methods

Women (N = 98) recently diagnosed with breast cancer and scheduled for breast and lymph node surgery completed questionnaires prior to surgery and at 3 months post‐surgery. Variables assessed included demographics, cognitive belief variables in relation to lymphedema and its management (perceived negative consequences, perceived lymphedema controllability, self‐efficacy, perceived personal risk, perceived self‐regulatory ability to manage risk‐related distress), lymphedema knowledge, trait anxiety and adherence to lymphedema risk management recommendations.

Results

Greater adherence was associated bivariately with greater beliefs in lymphedema controllability, self‐efficacy, perceived consequences and perceived self‐regulatory ability. Linear regression analyses revealed that only greater beliefs in the controllability of lymphedema and self‐regulatory ability, as well as greater knowledge, were predictive of greater adherence to risk management strategies.

Conclusions

This study highlights the importance of underlying beliefs as determinants of whether a woman who is informed and knowledgeable about lymphedema risk and its management will undertake the recommended risk management actions. Along with raising awareness of lymphedema and its risk management, health professionals should promote positive beliefs among women regarding the controllability of lymphedema through early‐detection/early‐treatment approaches. In addition, educational approaches should aim to enhance a woman's beliefs in her ability to adhere to these risk management recommendations over time. Copyright © 2012 John Wiley & Sons, Ltd.
Trophic inferences of blue shark (Prionace glauca) in the Mexican Pacific from stable isotope analysis in teeth
Authors: Polo‐Silva Carlos J. , Galván‐Magaña Felipe , Delgado‐Huertas Antonio
Published: June 2012

RATIONALE

Isotopic analysis of biogenic tissues such as teeth of elasmobranchs has been well recognized as an important method to interpret present and past environmental conditions. However, few studies on shark teeth have focused their attention on making trophic inferences or reconstruction of diet.

METHODS

We analyzed the carbon (δ13C) and nitrogen (δ15N) isotope composition of the tooth crown and root from blue sharks Prionace glauca caught in southern Baja California using a continuous‐flow system by means of an elemental analyzer combined with a Delta Plus XL mass spectrometer, to describe their feeding ecology, considering sex and maturity stage.

RESULTS

Significant differences in δ13C values for tooth root were found between immature and mature males, with depleted values of 13C in immature individuals. No statistical differences were found between maturity stages in females for both the C and N isotopes in any part of the tooth, which suggests that females were consuming the same prey in the same area. In addition, we observed significant differences in δ15N values between the tooth crown and root.

CONCLUSIONS

Isotopic analysis in the tooth crown (dentin) and root may represent a new tool to describe the feeding ecology of different species of elasmobranchs, showing dietary change over a short timescale. Copyright © 2012 John Wiley & Sons, Ltd.
The Application of STEM and In situ Controlled Dehydration to Bacterial Systems Using ESEM
Authors: Staniewicz Lech , Donald Athene M. , Stokes Debbie J. , Thomson Nicholas , Sivaniah Easan , Grant Andrew , Bulmer David , Khan Anjam
Published: June 2012

Transmission imaging with an environmental scanning electron microscope (ESEM) (Wet STEM) is a recent development in the field of electron microscopy, combining the simple preparation inherent to ESEM work with an alternate form of contrast available through a STEM detector. Because the technique is relatively new, there is little information available on how best to apply this technique and which samples it is best suited for. This work is a description of the sample preparation and microscopy employed by the authors for imaging bacteria with Wet STEM (scanning transmission electron microscopy). Three different bacterial samples will be presented in this study: first, used as a model system, is Escherichia coli for which the contrast mechanisms of STEM are demonstrated along with the visual effects of a dehydration‐induced collapse. This collapse, although clearly in some sense artifactual, is thought to lead to structurally meaningful morphological information. Second, Wet STEM is applied to two distinct bacterial systems to demonstrate the novel types of information accessible by this approach: the plastic‐producing Cupriavidus necator along with wild‐type and ΔmreC knockout mutants of Salmonella enterica serovar Typhimurium. Cupriavidus necator is shown to exhibit clear internal differences between bacteria with and without plastic granules, while the ΔmreC mutant of S. Typhimurium has an internal morphology distinct from that of the wild type. SCANNING 34: 237‐246, 2012. © 2012 Wiley Periodicals, Inc.
Quantifying Microwear on Experimental Mistassini Quartzite Scrapers: Preliminary Results of Exploratory Research Using LSCM and Scale‐Sensitive Fractal Analysis
Authors: Stemp W. James , Lerner Harry J. , Kristant Elaine H.
Published: June 2012

Although previous use‐wear studies involving quartz and quartzite have been undertaken by archaeologists, these are comparatively few in number. Moreover, there has been relatively little effort to quantify use‐wear on stone tools made from quartzite. The purpose of this article is to determine the effectiveness of a measurement system, laser scanning confocal microscopy (LSCM), to document the surface roughness or texture of experimental Mistassini quartzite scrapers used on two different contact materials (fresh and dry deer hide). As in previous studies using LSCM on chert, flint, and obsidian, this exploratory study incorporates a mathematical algorithm that permits the discrimination of surface roughness based on comparisons at multiple scales. Specifically, we employ measures of relative area (RelA) coupled with the F‐test to discriminate used from unused stone tool surfaces, as well as surfaces of quartzite scrapers used on dry and fresh deer hide. Our results further demonstrate the effect of raw material variation on use‐wear formation and its documentation using LSCM and RelA. SCANNING 35:28‐39, 2013. © 2012 Wiley Periodicals, Inc.
Characterization of Mass and Swelling of Hydrogel Microstructures using MEMS Resonant Mass Sensor Arrays
Authors: Millet Larry J. , Corbin Elise A. , Free Robert , Park Kidong , Kong Hyunjoon , King William P. , Bashir Rashid
Published: June 2012

The use of hydrogels for biomedical engineering, and for the development of biologically inspired cellular systems at the microscale, is advancing at a rapid pace. Microelectromechanical system (MEMS) resonant mass sensors enable the mass measurement of a range of materials. The integration of hydrogels onto MEMS resonant mass sensors is demonstrated, and these sensors are used to characterize the hydrogel mass and swelling characteristics. The mass values obtained from resonant frequency measurements of poly(ethylene glycol)diacrylate (PEGDA) microstructures match well with the values independently verified through volume measurements. The sensors are also used to measure the influence of fluids of similar and greater density on the mass measurements of microstructures. The data show a size‐dependent increase in gel mass when fluid density is increased. Lastly, volume comparisons of bulk hydrogels with a range polymer concentration (5% to 100% (v/v)) show a non‐linear swelling trend.
Early pregnancy screening for hypertensive disorders in women without a‐priori high risk
Authors: Abdelaziz A. , Maher M. A. , Sayyed T. M. , Bazeed M. F. , Mohamed N. S.
Published: June 2012

Objectives

To evaluate the performance of mean arterial pressure, uterine artery pulsatility index and soluble endoglin level alone or in combination in screening for hypertensive disorders in pregnant women without a‐priori high risk.

Methods

This was a nested case–control study of women with singleton pregnancies without a‐priori high risk who developed pregnancy‐induced hypertensive complications. Women were enrolled into the study at 11–14 weeks' gestation, when mean arterial pressure and uterine artery pulsatility index were recorded and a blood sample was taken for measurement of soluble endoglin. Women were followed up in the clinic to detect development of any hypertensive disorder. Each affected case was matched with two normotensive control women with uncomplicated pregnancies that resulted in phenotypically normal infants. Mean values for each variable were compared between cases and controls. Sensitivities, positive predictive values and negative predictive values at fixed specificity were derived from receiver–operating characteristics (ROC) curves.

Results

During the study period, 2120 patients were examined. Of these, 170 (8.02%) were excluded because they were lost to follow‐up and in 52 (2.45%) there was fetal death or miscarriage before 24 weeks' gestation. Thus, 1898 cases formed the cohort population. Of these, 89 (4.69%) patients developed complications (study group), including 16 (0.84%) cases with early pre‐eclampsia (PE), 60 (3.16%) with late PE and 13 (0.68%) with gestational hypertension (GH). There were 49 (2.58%) cases of spontaneous preterm delivery before 34 weeks. The rest of the cohort population (1760 (92.73%) patients, the base cohort) were not affected by PE or GH. The control group comprised 178 patients.

The best model for the prediction of any of the types of hypertensive disorders was one that combined mean arterial pressure with soluble endoglin (area under the ROC curve (AUC), 0.83). The predictive value of the three combined markers was highest for screening for early and late PE (AUC, 0.86 and 0.83, respectively). When each marker was considered alone, the highest prediction of any type of hypertensive disorder was achieved by mean arterial pressure (AUC, 0.73). Sensitivity was lowest for detection of GH when screening both by individual and by combined markers.

Conclusion

First‐trimester screening can be useful in predicting women at high risk of developing hypertensive disorders of pregnancy but more prospective longitudinal studies are needed. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Usefulness of lung‐to‐head ratio and intrapulmonary arterial Doppler in predicting neonatal morbidity in fetuses with congenital diaphragmatic hernia treated with fetoscopic tracheal occlusion
Authors: Cruz‐Martinez R. , Castañon M. , Moreno‐Alvarez O. , Acosta‐Rojas R. , Martinez J. M. , Gratacos E.
Published: June 2012

Objective

To explore the potential value of intrapulmonary artery Doppler velocimetry in predicting neonatal morbidity in fetuses with left‐sided congenital diaphragmatic hernia (CDH) treated with fetoscopic tracheal occlusion (FETO).

Methods

Observed/expected lung‐to‐head ratio (O/E‐LHR), and intrapulmonary Doppler pulsatility index and peak early‐diastolic reversed flow were evaluated within 24 h before FETO in a consecutive cohort of 51 fetuses with left‐sided CDH at between 24 and 33 weeks' gestation. Lung Doppler parameters were converted into Z‐scores and defined as abnormal if the pulsatility index had a Z‐score of > 1.0 or the peak early‐diastolic reversed flow had a Z‐score of > 3.5. The association of O/E‐LHR and Doppler velocimetry with neonatal outcome was assessed using multiple linear or logistic regression analysis adjusted for gestational age at birth.

Results

Among the 26 fetuses that survived, 18 (69.2%) had normal and eight (30.8%) had abnormal Doppler values. O/E‐LHR was not associated with neonatal morbidity in surviving fetuses. Compared with the group with normal Doppler parameters, cases with abnormal intrapulmonary Doppler were associated with a significant increase in the duration of mechanical ventilation (average increase of 21.2 (95% CI, 9.99–32.5) days; P < 0.01), conventional ventilation (15.2 (95% CI, 7.43–23.0) days; P < 0.01), high‐frequency ventilation (6.34 (95% CI, 0.69–11.99) days; P < 0.05), nitric oxide therapy (5.73 (95% CI, 0.60–10.9) days; P < 0.05), oxygen support (36.5 (95% CI, 16.3–56.7) days; P < 0.01), parenteral nutrition (19.1 (95% CI, 7.53–30.7) days; P < 0.01) and stay in neonatal intensive care unit (42.7 (95% CI, 22.9–62.6) days; P < 0.001), and with significantly higher rates of high‐frequency ventilation (87.5 vs 44.4%;P < 0.05), oxygen requirement at 28 days of age (75.0 vs 11.1%; P < 0.01), gastroesophageal reflux (62.5 vs 22.2%; P < 0.05) and tube feeding at discharge (37.5 vs 5.56%; P < 0.05).

Conclusion

As previously reported, O/E‐LHR did not predict neonatal morbidity. In contrast, intrapulmonary artery Doppler evaluation was predictive of neonatal morbidity in CDH fetuses treated with FETO.Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
MIRRORCLE type tabletop synchrotron light source realizing micron‐order focus point
Authors: Yamada Hironari , Maeo Shyoji , Hasegawa Daisuke , Yamada Mami , Yamada Takanori , Hayashi Taichi
Published: June 2012

MIRRORCLE generates brilliant far‐infrared, extreme ultraviolet, and hard X‐ray beams in a body of tabletop electron storage ring (ESR). In this paper, we report the most recent development of the 4‐ and 1‐MeV, 8‐cm orbit radius ESR. X‐rays are generated in Bremsstrahlung mechanism by a micron‐order ball shape target placed in the ESR electron orbit. Nature of the source is different from either X‐ray tubes or synchrotron light sources (SLS). MIRRORCLE generates high‐density photons such as SLS, but the emitter size is much smaller than that. The X‐ray angular distribution is 1/γ determined by the normalized electron energy γ, thus is much wider than of SLS with the MeV electrons. The energy spectrum is polychromatic like SLS but continues up to MeV range. MIRRORCLE has advantages in magnified phase contrast X‐ray 2D and 3D imaging for light as well as heavy materials. It has an advantage in fluorescent analysis of micron‐sized objects because focus size is in microns. It is advanced in an ultrasmall‐angle scattering experiment by its micron‐order focus point. Extended X‐ray absorption fine structure is carried out in an energy dispersive mode because of the white spectrum and the wide angular spread of radiation. Copyright © 2012 John Wiley & Sons, Ltd.
Ligandenaustauschreaktionen an Kupfer(II)‐Komplexen mit Harnstoffliganden: Synthesen, Strukturen, EPR‐Spektroskopie
Authors: Gruschinski Sina , Rodenstein Axel
Published: June 2012

The synthesis of copper(II) and nickel(II) complexes ofN,N‐diethyl‐N'‐benzoylurea HL1,N,N‐diethyl‐N'‐(2, 6‐difluorbenzoyl)urea HL2,N,N‐diethyl‐N'‐benzoylthiourea HL3,N,N‐diethyl‐N'‐(3, 4, 5‐trimethoxybenzoyl)thiourea HL4andN,N‐diethyl‐N'‐benzimidoylthiourea H2L5and the crystal structures of HL2,[Cu(L2)2]and[Ni(HL5)2]are reported. All CuIIcomplexes were investigated by EPR spectroscopy in liquid and frozen solutions. The CuIIcomplex[Cu(HL5)2]was additionally studied as diamagnetically diluted powder system[Ni(HL5)2] / [Cu(HL5)2](99:1). The calculation of electron spin‐density distribution in the first coordination sphere of[Cu(HL5)2]is represented, based on well‐resolved63, 65Cu and14N hyperfine structure (hfs) couplings. Ligand exchange reactions of CuIIcomplexes of urea type ligands HL1–4and H2L5were studied by means of EPR spectroscopy in liquid solutions. Statistical and quantitative runs were derived from concentration‐dependenthfsline intensities.
Condensed Double‐Chain Cluster Complexes with Seven‐Coordinate Endohedral Iridium Atoms in {Ir2Gd5}Br5
Authors: Brühmann Matthias , Meyer Gerd
Published: June 2012

Abstract. The new condensed double‐chain cluster complex compound {Ir2Gd5}Br5 was obtained from a reaction of GdBr3 with metallic gadolinium and iridium at elevated temperatures. The thin black needles crystallize with the orthorhombic crystal system, space group Pnma(no. 62); a = 1255.4(1) pm, b = 414.05(3) pm, c = 2633.8(3) pm,Z = 4, R1/wR2 = 0.0504/0.0346 for all data. Monocapped trigonal prisms of gadolinium atoms with endohedral iridium atoms are connected by common rectangular faces to chains and further by edges to double chains, which form a herringbone arrangement. The double chains are coordinated by bromido ligands and are connected in accord with the formulation {Ir2Gd5}Br4/2iBr2/3i(e)Br1/3i(f)Br2/2i–i(e/f)Br1/2i–aBr1/2a–i.
Zur Elektronenstruktur hochsymmetrischer Verbindungen der f‐Elemente. 45[1]Ungewöhnliche spektrochemische Eigenschaften des Triphenylphosphanoxido‐Liganden im Falle von Mono‐ und Bisaddukten homoleptischer Samarium(III)silylamide
Authors: Jank Stefan , Reddmann Hauke , Zhang Lixin , Amberger Hanns‐Dieter
Published: June 2012

The optical spectra of the mono tetrahydrofuran (1), mono triphenylphosphinoxide (2) and bis cyclohexylisocyanide (3) adducts of the tris(bis(trimethylsilyl)amido)samarium(III) (Sm(btmsa)3) moiety as well as those of the bis tetrahydrofuran (4) and partly those of the bis triphenylphosphinoxide (5) of the tris(bis(dimethylsilyl)amido)samarium(III) moiety have been recorded at room and low temperatures. From the spectra obtained, the underlying crystal field splitting patterns could be derived, and simulated by fitting the free parameters of a phenomenological Hamiltonian. The values of the crystal field parameters B$\rm^{2}_{0}$ of the OPPh3 adducts are much less negative than those of the remaining adducts or that of the base free compound.
Pancreas‐Sparing Total Duodenectomy for Ampullary Duodenal Neoplasms
Authors: Stauffer John A. , Adkisson Cameron D. , Riegert‐Johnson Douglas L. , Goldberg Ross F. , Bowers Steven P. , Asbun Horacio J.
Published: June 2012

Background

Ampullary and extensive periampullary lesions can be difficult to treat and often require pancreaticoduodenectomy (PD) for complete removal, even if benign. However, PD may be overtreatment for noninvasive lesions, and pancreas‐sparing total duodenectomy (PSTD) is an emerging valid surgical option for selected cases.

Methods

We reviewed patients undergoing PSTD at our institution over 16 months and a comparison group who had undergone PD for benign duodenal disease over the past 15 years. We also reviewed cases in the English‐language literature and performed a meta‐analysis of those patients who had undergone PSTD.

Results

PSTD had been performed in four patients, who had an average hospital length of stay (LOS) of 13 days; two of them experienced complications. None required conversion to PD, experienced a postoperative fistula or endocrine or exocrine insufficiency, or required intensive care. Two of the PSTDs were performed laparoscopically. Open PD for benign duodenal disease was performed in 22 patients, with overall morbidity and pancreas fistula rates of 82 and 27 %, respectively. The meta‐analysis found 128 unique cases of PSTD with morbidity and mortality rates of 46.4 and 2.3 %, respectively. Pancreaticobiliary leak was seen in 20 %, with an average LOS of 17 days.

Conclusions

Although PSTD can be used to avoid PD and can be performed laparoscopically, it is technically challenging and still associated with morbidity.
Reducing Youth Access to Alcohol: Findings from a Community‐Based Randomized Trial
Authors: Flewelling Robert L. , Grube Joel W. , Paschall M. J. , Biglan Anthony , Kraft Anne , Black Carol , Hanley Sean M. , Ringwalt Christopher , Wiesen Chris , Ruscoe Jeff
Published: June 2012

Underage drinking continues to be an important public health problem and a challenge to the substance abuse prevention field. Community‐based interventions designed to more rigorously control underage access to alcohol through retailer education and greater enforcement of underage drinking laws have been advocated as potentially effective strategies to help address this problem, but studies designed to evaluate such interventions are sparse. To address this issue we conducted a randomized trial involving 36 communities to test the combined effectiveness of five interrelated intervention components designed to reduce underage access to alcohol. The intervention was found to be effective in reducing the likelihood that retail clerks would sell alcohol to underage‐looking buyers, but did not reduce underage drinking or the perceived availability of alcohol among high school students. Post hoc analyses, however, revealed significant associations between the level of underage drinking law enforcement in the intervention communities and reductions in both 30‐day use of alcohol and binge drinking. The findings highlight the difficulty in reducing youth drinking even when efforts to curtail retail access are successful. Study findings also suggest that high intensity implementation of underage drinking law enforcement can reduce underage drinking. Any such effects of enhanced enforcement on underage drinking appear to be more directly attributable to an increase in perceived likelihood of enforcement and the resultant perceived inconveniences and/or sanctions to potential drinkers, than to a reduction in access to alcohol per se.
Image-based 3D modeling and validation of radiofrequency interstitial tumor ablation using a tissue-mimicking breast phantom
Authors: Wang Zhigang , Aarya Isshaa , Gueorguieva Mariana , Liu Dun , Luo Hongyan , Manfredi Luigi , Wang Lijun , McLean Donald , Coleman Stuart , Brown Stuart , Cuschieri Alfred
Published: June 2012

Purpose

Minimally invasive treatment of solid cancers, especially in the breast and liver, remains clinically challenging, despite a variety of treatment modalities, including radiofrequency ablation (RFA), microwave ablation or high-intensity focused ultrasound. Each treatment modality has advantages and disadvantages, but all are limited by placement of a probe or US beam in the target tissue for tumor ablation and monitoring. The placement is difficult when the tumor is surrounded by large blood vessels or organs. Patient-specific image-based 3D modeling for thermal ablation simulation was developed to optimize treatment protocols that improve treatment efficacy.

Methods

A tissue-mimicking breast gel phantom was used to develop an image-based 3D computer-aided design (CAD) model for the evaluation of a planned RF ablation. First, the tissue-mimicking gel was cast in a breast mold to create a 3D breast phantom, which contained a simulated solid tumor. Second, the phantom was imaged in a medical MRI scanner using a standard breast imaging MR sequence. Third, the MR images were converted into a 3D CAD model using commercial software (ScanIP, Simpleware), which was input into another commercial package (COMSOL Multiphysics) for RFA simulation and treatment planning using a finite element method (FEM). For validation of the model, the breast phantom was experimentally ablated using a commercial (RITA) RFA electrode and a bipolar needle with an electrosurgical generator (DRE ASG-300). The RFA results obtained by pre-treatment simulation were compared with actual experimental ablation.

Results

A 3D CAD model, created from MR images of the complex breast phantom, was successfully integrated with an RFA electrode to perform FEM ablation simulation. The ablation volumes achieved both in the FEM simulation and the experimental test were equivalent, indicating that patient-specific models can be implemented for pre-treatment planning of solid tumor ablation.

Conclusion

A tissue-mimicking breast gel phantom and its MR images were used to perform FEM 3D modeling and validation by experimental thermal ablation of the tumor. Similar patient-specific models can be created from preoperative images and used to perform finite element analysis to plan radiofrequency ablation. Clinically, the method can be implemented for pre-treatment planning to predict the effect of an individual’s tissue environment on the ablation process, and this may improve the therapeutic efficacy.
Volume, volatility and information linkages in the stock and option markets
Authors: Ho Kin‐Yip , Zheng Lin , Zhang Zhaoyong
Published: June 2012

This paper examines the relationship between option trading activity and stock market volatility. Although the option market is uniquely suited for trading on volatility information, there is little analysis on how trading activity in this market is linked to stock price volatility. The bulk of the discussion tends to focus on whether trading activity in the stock market is informative about stock volatility. To analyze the information in option trading activity for stock market volatility, a sample of 15 stocks with the highest option trading volume is selected. For each stock, it is noted that the trading activities in the put and call option markets have significant explanatory power for stock market volatility. In addition, the results indicate that the call option trading activity has a stronger impact on stock volatility compared with that of the put options. Our results demonstrate that information and sentiment in the option market is useful for the estimation of stock market volatility. Also, the significance of the effects of option trading activity on stock price volatility is observed to be comparable to that of stock market trading activity. Furthermore, the persistence and asymmetric effects in the volatility of some stocks tend to disappear once option trading activity is taken into account.
Stocks, Bonds, and Long-Run Consumption Risks
Authors: Hasseltoft Henrik
Published: June 2012

I evaluate whether the so-called long-run risk framework can jointly explain key features of both equity and bond markets as well as the interaction between asset prices and the macroeconomy. I find that shocks to expected consumption growth and time-varying macroeconomic volatility can account for the level of risk premia and its variation over time in both markets. The results suggest a common set of macroeconomic risk factors operating in equity and bond markets. I estimate the model using a simulation estimator that accounts for time aggregation of consumption growth and utilizes a rich set of moment conditions.
III.—An Experiment in Marine Fish Cultivation: III. The Plankton of a Fertilized Loch
Authors: Marshall Sheina M.
Published: June 2012

The plankton in Loch Craiglin was sampled at Station I, the deepest part of the loch. Samples were taken at intervals of two or three weeks, and since, as is mentioned below, the sampling of zooplankton was unreliable for part of 1942, the results for that year are referred to only briefly and the more complete results of 1943 given in detail.
VIII.—Variation in Shape of Shell with Respect to Ecological Station. A Review dealing with Recent Unionidæ and Certain Species of the Anthracosiidæ in Upper Carboniferous Times
Authors: Eagar R. M. C.
Published: June 2012

Studies in the variation of the Anthracosiidæ (= Carbonicolidæ) in the South Wales Coalfield by Davies and Trueman (1927) and in the Scottish Coalfields by Leitch (1936, 1940, 1941) have suggested that environmental influence on shell form is confined to changes in thickness of shell and in obesity. Davies and Trueman quoted H. R. Wakefield, who remarked that to-day among the Unionidæ these characters appear to vary according to the station of the shells in a single lake. Leitch referred to the work of Ortmann (1920) on the relation between obesity and distribution of river mussels in a large drainage basin in the U.S.A. The writer, in the course of very detailed work on the most highly variable faunas of the Anthracosiidæ known in the British Coal Measures, found evidence suggesting that certain other changes in shell shape and dimensions may also accompany environmental changes, as far as past environments may be reflected in the lithology of the rocks containing the shells.
Studies in Penicillin Formation.
Authors: Cook R. P. , Brown Margaret B.
Published: June 2012

Synopis

Extracts of green peas stimulate penicillin formation byPenicillium notatum, and fractions have been prepared by treating the juice with ethanol to find the constituents present which have a stimulating action. The mould has been grown as a surface culture on a basal medium containing NaNO3, KH2PO4, MgSO4, NaCl and lactose to which the various fractions have been added. One chemically complex fraction containing a large number of amino acids (demonstrated by paper partition chromatography and estimated micro-biologically), carbohydrates and mineral matter (containing a number of trace elements) gives high yields of penicillin. The types of penicillin produced on this medium have been determined by micro-chromatography.

Chemically defined media have been formulated, and information has been obtained on the sources of carbon and nitrogen that permit growth and penicillin formation.

The amounts of carbohydrate and salts in the medium influence the formation of penicillin. Excess of carbohydrates such as glucose cause an increase in growth of the mould and a decrease in the production of penicillin.

The significance of the results in relation to the formation of penicillin is discussed.
Behaviour of the Ring-Chromosome inDrosophila Melanogaster
Authors: Battacharya P.
Published: June 2012

Synopis

The genetical studies on ring-chromosomes inDrosophilashow that there is no interlocking of chromatids at mitosis.

Dicentric ring-chromosomes formed at meiosis on being pulled apart do not become broken with subsequent reunion of the broken ends. This may be due to the failure of these chromosomes either to rejoin or to become broken at all.

The results make it probable that there is a gene or genes located in one of chromocentral regions of the X-chromosome ofDrosophila, probably in the region at the distal end, which has a function in ensuring the orderly segregation of the chromatids in the early cleavage stages of the fertilised eggs. Hence the absence of this chromosome region results in a tendency to gynandromorphism.

Results indicate the incorrectness of the view that the inviable zygotes and the patroclinous males found in the ring-chromosome stock arise from different kinds of eggs (single cross-over and progressive double cross-over respectively, as proposed by L. V. Morgan). Both arise from eggs that have for any reason failed to receive a monocentric X-chromosome. This result occurs in all cases of digressive double crossing-over and in half the cases of progressive double crossing-over. Such virtually X-less eggs, when fertilised by an X-bearing sperm, form patroclinous males, and when fertilised by a Y-bearing sperm, form inviable zygotes. The classes thus found are therefore equal in number.
VII.—On Migrations ofLymnœa peregra(Müller) on the Shores of Loch Lomond
Authors: Hunter W. Russell
Published: June 2012

Synopsis

Seasonal changes in the distribution ofLymnœa peregra(Müller) on a gently sloping beach of Loch Lomond have been studied in detail, with particular reference to the effects of the changes in water level which occur. At lower water temperatures the distribution can be correlated with the availability of food. At higher water temperatures the respiratory needs of adult snails cause them to remain close to the water's edge, even in the absence of food. This is not always true of young snails. Measurement of the fæces produced by such adult snails gives further evidence that a degree of starvation can occur for short periods in the summer months.

Comparative data on the characteristics of the physical environment and the general distribution of gastropods in Loch Lomond are given, and the study discussed in relation to previous work on the littoral ecology of large lakes.
VIII.—Transuterine (“Internal”) Migration of Fertilised Ova in the Albino Rat
Authors: Young A. , Wyburn George M.
Published: June 2012

Synopsis

The passage of ova down the Fallopian tube and uterine horn of one side into the horn of the other side is generally referred to as transuterine migration. There is evidence that such transmigration can occur in a wide variety of animals—Ungulata, Carnivora, Cheiroptera, Insectivora and Primates (Boyd, Hamilton and Hammond, 1944; Marshall'sPhysiology of Reproduction, 1952). In all these forms the genital tract has a single supravaginal segment varying from a common cervical canal to the single uterine cavity of the primate uterus simplex. The uterus of the albino rat is generally described as “uterus duplex”, with separate cervical canals opening independently into the vagina, and it has been stated by Hanson and Boone (1925, 1926) and by Slonaker (1927) that there is no evidence that transuterine migration occurs in the albino rat. In the course of an experimental investigation of the vascular pattern in pregnancy in the rat, some results were obtained which indicate that transuterine migration can occur in the albino rat.
I—Nigrosin-Eosin Staining of Rabbit Spermatozoa and the Fertility of Semen
Authors: Beatty R. A.
Published: June 2012

Synopsis

A standard nigrosin-eosin staining method in current use has been said to differentiate between live (unstained) and dead (stained) spermatozoa. In the present work, the method is applied to rabbit semen. The general results are comparable with those already obtained in the larger domestic animals. The effects of several technical and biological factors on staining capacity are evaluated, and the validity of the method is examined experimentally. Some statistical aspects are presented. The percentage of stained spermatozoa varies widely between rabbit males. To a large extent, any particular male preserves a characteristic percentage from one ejaculate to another. The percentage of stained spermatozoa is inversely related to the fertility of males as measured by the birth rate after natural mating.

Concurrently, an investigation was made of the incidence of a class of morphologically abnormal spermatozoa seen in the preparations. The classifications of spermatozoa by morphology and by staining capacity are highly correlated. For assessing semen quality, the morphological classification is considered to be as useful as the classification by staining capacity, and perhaps more useful.

Nigrosin-eosin staining of rabbit spermatozoa is discussed; firstly, in comparison with other animals and in relation to sources of variation; secondly, as a means of differentiating between live and dead spermatozoa; thirdly, as a means of assessing the fertility of semen; and fourthly, in relation to the alternative classification of spermatozoa by abnormal morphology.
X.—A Taxonomic Review of the British Species of Culicoides Latreille (Diptera, Ceratopogonidæ).
Authors: Campbell J. Allan , Pelham-Clinton E. C.
Published: June 2012

Synopsis

A taxonomic review is provided of imagines of the forty-one known British species of Culicoides Latreille (Diptera, Ceratopogonidæ).

Four species new to science, C. cameroni, C. reconditus, C. segnis and C. machardyi are described from the British Isles.

The female of C. poperinghensis Goetghebuer is described for the first time. C. poperinghensis Goetghebuer and C. subfasciipennis Kieffer are recorded as new to the British Isles. C. lupicaris Downes and Kettle is defined anew. Distinguishing taxonomic characters are given for the females of C. achrayi Kettle and Lawson and C. pallidicornis Kieffer.

A number of female structural characters of taxonomic importance are discussed and described for all the British species: the antennal sensilla are found to be important as a group character and antennal ratio as a specific or subspecific character.

Descriptive notes with relevant taxonomic discussion are given for each species. The paper includes a key to species based on superficial characters and separate keys for each sex based on structural characters.
XIII.—The Cytology of a Diploid Bisexual Spider Beetle, Ptinus clavipes Panzer and its Triploid Gynogenetic form mobilis Moore
Authors: Sanderson Ann R.
Published: June 2012

Synopsis

The chromosome constitution of the bisexual beetle Ptinus clavipes Panzer (2n = 18) and of its gynogenetic form P. clavipes f. mobilis Moore (3n = 27) have been investigated. The triploid mobilis lives in close association with the bisexual species and mates freely with the males. Eggs from virgin females never pass beyond the metaphase stage and successful completion of maturation is dependent on the presence of sperm. An endomitotic split is apparent in prophase chromosomes and leads to the formation of twenty-seven pseudobivalents which undergo a pseudomeiotic division. Only one maturation division has been observed. Although the fate of the activating sperm has not been resolved it is thought that sperm nuclei give rise to isolated haploid nuclei in some eggs and interfere with normal cleavage in others. Since the triploid form may also mate with males of Ptinus pusillus Sturm and P. fur. L. with reduced numbers of progeny the affinities of the gynogenetic form is discussed. This is the only known case of gynogenesis in Coleoptera.
XIII.—The Polysaccharides Synthesized byMonodus subterraneuswhen Grown on Artificial Media under Bacteria-free Conditions.
Authors: Beattie Anne , Percival Elizabeth
Published: June 2012

Synopsis

This paper describes the isolation and characterization of the polysaccharides synthesized by the unicellular organism,Monodus subterraneus. Complete extraction of polysaccharide material proved difficult and the method finally adopted, after removal of colouring matter by immersion in dimethyl sulphoxide, was successive extractions with (i) cold water, (ii) hot water, (iii) aqueous ethanol, (iv) chlorite solution, and (v) dilute alkali. The major polysaccharide, isolated from (v), is a glucan. It was shown by periodate oxidation, methylation and enzymic studies to consist mainly ofβ-l, 4-linked glucose units. The presence of a small proportion ofβ-1, 3-linked glucose units, either incorporated with theβ-1, 4-linked units in a single polymer of the lichenin-type or in a separate polymer of the laminarin-type, was also established. Further small quantities of this mixed glucan were also deposited from (ii) and from (iii) on keeping these extracts in the cold. Heterogeneous crude polysaccharide material was isolated from (i), (ii), (iii) and (iv) by alcohol precipitation. The sugars present in these various precipitates and their respective oxopolysaccharides were identified chromatographically, and, in the case of the major constituents, separated and characterized as crystalline derivatives. The polysaccharide extracted by cold water was found to contain glucose, mannose, galactose, xylose and 12 per cent of sulphate; that extracted by hot water comprised glucose (major), galactose (major), and possibly fucose; and that extracted by chlorite solution consisted of glucose (major), xylose (major), ribose and a trace of galactose.
XIV.—Origin and Development of the Digestive System of the Giant Land SnailAchatina fulicaBowdich
Authors: Ghose Krishna Chandra
Published: June 2012

Synopsis

The stomodæum appears as an ectodermal invagination. The oesophagus develops from an outgrowth (posterior) and the radular sac from a ventral evagination of the floor of the stomodæum. The basal epithelium of the radular sac secretes the radular membrane and the teeth, while the dorsal epithelium contributes towards the hardening of the teeth. The subradular cavity is formed from a depression of the floor and the salivary glands from two evaginations of the roof of the stomodæum. The buccal cartilage is mesodermal, while the jaw is ectodermal. The blastopore closes. Only the posterior part of the archenteron takes part in the formation of the gut, from which the crop, stomach and the digestive gland develop. The anterior chamber of the crop develops from a diverticulum of the archenteron. The anterior and posterior lobes of the digestive gland arise from the anterior part of the primitive stomach dorsally and on the left side respectively; the posterior chamber of the crop from the anteroventral region of the primitive stomach, and the stomach from the posterior right side of its floor. The hind gut appears by the arrangement of cells proliferated from that part of the archenteron where blastopore closes. It opens anterodorsally into the primitive stomach in a 2½ mm. embryo; the anus appears in a late embryo about 12 days old.
XX.—Quantitative Studies on the Invertebrate Fauna of Sandy and Stony Substrates in the River Endrick, Scotland
Authors: Maitland Peter S.
Published: June 2012

Synopsis

Monthly quantitative samples of the invertebrate fauna were taken from two stations in the River Endrick over a period of fifteen months; the substrate at one station in the lower reaches was sandy, whilst that at the other in the middle reaches was stony. The fauna at these stations differed qualitatively, but showed certain quantitative similarities, especially with regard to seasonal change. The fauna of stones is richer, and much more varied than that of sand, though both substrates appear to be unstable and may be drastically affected by spates. The average standing crop of the invertebrate fauna during 1960 was found to be 8 g. per square m. in sand and 16 g. per square m. in stones. Compared with the few other results which are available for rivers elsewhere in the world these figures would indicate that the standing crops of these substrates in the River Endrick are of intermediate richness.
XXII.—A Quantitative Study of Spermatozoan Nucleus Length inDrosophila melanogaster(Meig).
Authors: Sidhu N. S.
Published: June 2012

Synopsis

A squash-preparation technique for the measurement of nucleus lengths in permanent preparations of the spermatozoa ofDrosophila melanogasteris described. Prefixation gave longer nuclei, but the degree of pressure used in making the squash did not affect nucleus length. Variation in nucleus length between the spermatozoa of a male was fairly high (coefficient of variation 14 per cent). Smaller, though significant, differences existed between means of males within culture bottles, but there were no significant differences between means of duplicate culture bottles. There was a little evidence of heterogeneity of within-male variances. A logarithmic transformation of data before analysis was indicated. These observations provide a hitherto missing background for planning experiments in quantitative variation designed to throw light on genetic and other factors affecting the dimensions ofDrosophilaspermatozoa.
VII.—On the Neonatus of Callimico gœldii (Thomas)
Authors: Osman Hill W. C.
Published: June 2012

Synopsis

An account is provided of the external and skeletal features of a four-days old Callimico gœldii, one of twins born in captivity. Bodily proportions are compared with those of other newborn marmosets and tamarins. Diffeiences in pelage from the adult are outlined. Data are provided on the regional external anatomy. The state of skeletal ossification and dental development are discussed. The taxonomic position of Callimico within the Hapalidæ is confirmed.