bluuebunny/crossref_metadata_2025 huggingface dataset:
Mortality from infectious diseases among refugees and immigrants compared to native Danes: a historical prospective cohort study
Authors: Norredam M. , Olsbjerg M. , Petersen J. H. , Bygbjerg I. , Krasnik A.
Published: October 2011

Objectives  Refugees and immigrants are likely to be vulnerable to mortality from infectious diseases as a result of high prevalences in their countries of origin and barriers in access to healthcare in the recipient countries. Consequently, we aimed to compare and investigate differences in mortality from infectious diseases among refugees and immigrants and native Danes.

Methods  A register‐based, historical prospective cohort design. All refugees (n = 29 139) and family‐reunited immigrants (n = 27 134) who, between 1 January1993 and 31 December1999, were granted the right to reside in Denmark were included and matched 1:4 on age and sex with native Danes. Civil registration numbers were cross‐linked to the Register of Causes of Death, and fatalities owing to infectious diseases (based on ICD‐10 diagnosis) were identified. Mortality ratios were estimated separately for men and women by migrant status and region of birth; adjusting for age and income; using a Cox regression model, after a mean follow‐up of 10–12 years after arrival.

Results  Female [hazard ratio (HR) = 4.15; 95% CI: 2.38, 7.25] and male (HR = 2.05; 95% CI: 1.27, 3.33) refugees experienced significantly higher mortality risks from infectious diseases than did native Danes, as was the case for male immigrants (HR = 2.39; 95% CI: 1.20, 4.76) but less so for female immigrants (HR = 1.23; 95% CI: 0. 50‐3.01). Mortality by region of origin was notably higher for individuals from North Africa and sub‐Saharan Africa.

Conclusions  Higher mortality among refugees and immigrants than among the native population should lead to reflections on medical reception systems in recipient countries and subsequent possibilities of access to specialised diagnostic and curative healthcare.
Difference in keratinase activity of dermatophytes at different environmental conditions is an attribute of adaptation to parasitism
Authors: Sharma Anima , Chandra Subhash , Sharma Meenakshi
Published: October 2011

Dermatophytes are a group of morphologically and physiologically related moulds, which cause well‐defined infection called dermatophytosis. The enzymatic ability of fungi to decompose keratin has long been interpreted as a key innovation in the evolution of animal dermatology. In the present study, keratinase activity profile among Trichophyton mentagrophytes, Trichophyton rubrum, Microsporum canis and Microsporum gypseum isolated on keratin substrates such as human hair, human nail and chicken feather at variable environmental conditions of temperature, pH and metal ions was elucidated. All the above‐mentioned fungal strains were isolated from soil using To‐KA‐Va baiting technique and keratinolytic activity was measured spectrophotometrically. In the temperature range of 30–40 °C and slightly alkaline pH (7.0–8.0), Trichophyton produced the highest activity of keratinase. It can be presumed that high enzyme production of Trichophyton species at normal body temperature range and pH could be an attribute for obligate anthropization in some dermatophytes.
Changes of renal vitamin D metabolic enzyme expression and calcium transporter abundance in obstructive nephropathy
Authors: ZHANG YAN , WU SHU‐YAN , GU SA‐SA , LV FU‐KOU
Published: October 2011

The effects of urinary‐tract obstruction on renal function have been clarified. However, there is little known about the change of renal vitamin D metabolic enzyme expression and vitamin D‐dependent calcium transporting proteins expression in obstructive nephropathy. The male mice were subjected to unilateral ureteral obstruction (n = 10) or sham operation (n = 10). All mice were killed on day 7 after the surgical operation. Kidney sections were stained with Masson's trichrome and gene expression was analyzed by reverse transcription‐polymerase chain reaction (RT‐PCR) and real‐time PCR. The obstructed kidney exhibited interstitial fibrosis as shown by the strong collagen deposition in the interstitium. Quantitative PCR results showed the increase of 1‐OHase (P < 0.001) mRNA expression and the decrease of 24‐OHase (P < 0.01), CaBP‐9k (P < 0.01) and CaBP‐28k (P < 0.01) mRNA expression in obstructed kidney as compared to that of the Sham group. In addition, the mRNA expression of 1‐OHase and CaBP‐9k was significantly increased and decreased, respectively, in obstructed kidney as compared to that of the contra‐lateral kidney in unilateral ureteral obstruction (UUO) mice. Together, the present finding supports the hypothesis that the ureteral obstruction leads to the alteration of renal vitamin D metabolic enzyme expression and calcium transporter abundance, which may secondarily induce the abnormality of vitamin D endocrine system and bone health.
Leukaemic transformation of Philadelphia chromosome‐negative myeloproliferative neoplasms: are Asian patients different?
Authors: Cherian R. , Wong G. C.
Published: October 2011

Background:  Leukaemic transformation (LT) is rare in the natural history of Philadelphia(Ph) chromosome‐negative myeloproliferative disorders (MPD), and has a dismal prognosis. Little literature is available on Asian patients.

Aims:  The aim of this study is to report a single institution experience of Asian patients who developed acute leukaemia after being diagnosed and treated for Ph chromosome‐negative MPDs, and to compare the findings of this series with similar studies from the literature.

Methods:  Patients were recruited from the MPD registry of Singapore General Hospital, Department of Hematology. Clinical data including treatment modalities and duration of use in myeloproliferative phase, latency to LT, characteristics of leukaemia, chemotherapy administered and survival after LT were examined.

Results:  Over a 29‐year period from 1980 to 2009, there were 22 Asian patients with LT of Ph chromosome‐negative MPD of which four had polycythaemia vera (PV), nine had essential thrombocythaemia (ET), seven had myelofibrosis (MF) and two had unspecified MPD at diagnosis. Primary treatment modality was Hydroxyurea (HU) during MPD phase. Median latency to LT was 14 years for PV, 10 years for ET and 1 year for MF. Median age at LT diagnosis was 67.5 years. Nine patients had complex cytogenetics, with abnormalities of chromosomes 5 and 7 being common.

Overall, median survival was 2 months after LT. Eight patients who received induction chemotherapy had a median survival of 2.5 months. Survival was independent of MPD type and treatment administered. None received stem cell transplantation.

Conclusions:  LT of Ph chromosome‐negative MPD is rare and uniformly fatal. Despite chemotherapy, survival was poor, and patients succumbed to refractory disease and infections. Asian patients did not have a more favourable outcome. It remains to be investigated whether upfront stem cell transplant may be a treatment option.
‘A Science of Tonal Love’? Drive and Desire in Twentieth‐Century Harmony: the Erotics of Skryabin
Authors: SMITH KENNETH
Published: October 2011

Leonid Sabaneyev attested that Skryabin's compositions contained within them ‘a science of tonal love’, and Skryabin himself described his two Op. 57 pieces –Désir and Caresse dansée– as ‘new ways of making love’. But what makes this music so erotic in nature? The composer theorised about the nature of desire and sexuality in his writings, but this discussion rarely spills over into analysis of his compositional system. Given that Skryabin was so steeped in psychology throughout his life, I appeal to the work of Freud and Jacques Lacan, and particularly to their distinction between drive and desire (essentially, the fundamental instinct of the id versus its imaginary representation), a distinction found in Skryabin's own philosophical writings. But the progression between these two states bears comparison with both his philosophy and his harmonic processes, and I thus focus on the function of the dominant chord, exploring ways in which it can replicate the structures of drive and desire. In so doing, I scrutinise several piano miniatures to show that part of Skryabin's method of embodying drive in music lays out ambiguous chord structures which bear simultaneous tendencies to move in a number of different directions, as multivalent as the drive in the human subject. Further, I attempt to show that, out of mystical sonorities, Skryabin temporally unfolds a dialogue of different dominant ‘drives’, and eventually selects and nurtures a single one at the expense of others, a motion equivalent to desire.
Ethnic Differences in Appointment‐Keeping and Implications for the Patient‐Centered Medical Home—Findings from the Diabetes Study of Northern California (DISTANCE)
Authors: Parker Melissa M. , Moffet Howard H. , Schillinger Dean , Adler Nancy , Fernandez Alicia , Ciechanowski Paul , Karter Andrew J.
Published: October 2011

Objective

To examine ethnic differences in appointment‐keeping in a managed care setting.

Data Sources/Study Setting

Kaiser Permanente Diabetes Study of Northern California (DISTANCE), 2005–2007, n = 12,957.

Study Design

Cohort study. Poor appointment‐keeping (PAK) was defined as missing >1/3 of planned, primary care appointments. Poisson regression models were used to estimate ethnic‐specific relative risks of PAK (adjusting for demographic, socio‐economic, health status, and facility effects).

Data Collection/Extraction Methods

Administrative/electronic health records and survey responses.

Principal Findings

Poor appointment‐keeping rates differed >2‐fold across ethnicities: Latinos (12 percent), African Americans (10 percent), Filipinos (7 percent), Caucasians (6 percent), and Asians (5 percent), but also varied by medical center. Receiving >50 percent of outpatient care via same‐day appointments was associated with a 4‐fold greater PAK rate. PAK was associated with 20, 30, and 40 percent increased risk of elevated HbA1c (>7 percent), low‐density lipoprotein (>100 mm/dl), and systolic blood pressure (>130 mmHg), respectively.

Conclusions

Latinos and African Americans were at highest risk of missing planned primary care appointments. PAK was associated with a greater reliance on same‐day visits and substantively poorer clinical outcomes. These results have important implications for public health and health plan policy, as primary care rapidly expands toward open access to care supported by the patient‐centered medical home model.
Electrical and Thermal Properties of Cr2GeC
Authors: Barsoum M. W. , Scabarozi T. H. , Amini S. , Hettinger J. D. , Lofland S. E.
Published: October 2011

Herein we report on the 4–300 K resistivity, magnetoresistance, Hall and Seebeck coefficients and heat capacity of Cr2GeC. The results—analyzed within a two‐band model—confirm that Cr2GeC is a compensated conductor where the concentration of electrons and holes are almost equal; the same is true of the mobilities. The room‐temperature thermal conductivity is 22 W·(m·K)−1; roughly half the heat is carried by phonons, half by electrons. The heat capacity results confirm previous results.
c/a Ratio‐Dependent Energy‐Storage Density in (0.9−x)Bi0.5Na0.5TiO3–xBaTiO3–0.1K0.5Na0.5NbO3 Ceramics
Authors: Gao Feng , Dong Xianlin , Mao Chaoliang , Cao Fei , Wang Genshui
Published: October 2011

The (0.9−x)Bi0.5Na0.5TiO3–xBaTiO3–0.1K0.5Na0.5NbO3 [BNBKN(x), x = 0.060, 0.063, 0.066, and 0.069] ceramics were fabricated by the conventional sintering technique. The P–E hysteresis loops measured under 5 kV/mm at room temperature show that the BNBKN(0.063) ceramics obtain the maximum (Ps−Pr) value of 20.6 μC/cm2 and the largest energy‐storage density W of 0.424 J/cm3. In addition, calculation from the X‐ray diffraction results shows that the BNBKN(0.063) ceramics are featured with the largest c/a ratio of 0.70887. The W is observed to increase with the increase of the c/a ratio in the BNBKN(x) ceramics. The c/a ratio can be regarded as a significant factor for W in the BNBKN(x) ceramics.
Solid‐State Reactive Sintering and Optical Characteristics of Transparent Er:YAG Laser Ceramics
Authors: Li Jiang , Zhou Jun , Pan Yubai , Liu Wenbin , Zhang Wenxin , Guo Jingkun , Chen Hao , Shen Deyuan , Yang Xiaofang , Zhao Ting
Published: October 2011

Highly transparent Er:YAG ceramics were fabricated by solid‐state reactive sintering using a mixture of commercial α‐Al2O3, Y2O3, and Er2O3 powders with tetraethoxysilane and MgO as sintering aids. A fully dense 1.0 at.% Er:YAG ceramic with an average grain size of ~25 μm was obtained by vacuum sintering at 1800°C for 30 h. The in‐line transmittance reached 83% near the lasing wavelength of 1645 nm with a scattering loss of ~0.02 cm−1. Laser operation of such a Er:YAG ceramic rod (4.0 mm × 4.0 mm × 10.8 mm) was demonstrated at 1645 nm with a slope efficiency of 51% under resonant pumping at 1532 nm, and the maximum continuous‐wave laser output was 13 W.
Jichengite 3CuIr2S4·(Ni, Fe)9S8, a New Mineral, and Its Crystal Structure
Authors: YÜ Zuxiang , HAO Ziguo , WANG Hanggen , YIN Shuping , CAI Jianhui
Published: October 2011

A new mineral, jichengite ideally 3CuTr2S4·(Ni,Fe)9S8, was found as a constituent of placer concentrates at a branch of the Luanhe River, about 220 km NNE of Beijing. Its associated minerals are chromite, magnetite, ilmenite, zircon, native gold, iridium, ferrian platinum and osmium. The placer is distributed at places around ultrabasic rock, which hosts chromite orebodies, from which PGM originated. Jichengite occurs commonly as massive or granular aggregates. No perfect morphology of jichengite was observed. It is steel gray and opaque with metallic luster and black streak. It has a Mohs hardness of 5, VHN (d) μm 21.65, Hm 4.465, Hv = 268.1 N/um2. It is brittle and weakly magnetic. Cleavage {010} is rarely observed. No fracture was observed. Density could not be measured because of its too small grain size. Density (calc.) is 7.003 g/cm3. Reflect light is reddish‐brown, without internal reflections. Anisotropism is distinct with grayish or yellowish white in crossed nicols and bluish violet‐copper red in uncrossed nicols. Jichengite shows weak pleochroism and strong bireflectance. The reflectance values in air at the Standard Commission on Ore Mineralogy wavelengths are: 38.9, 34.3 at 470 nm, 38.9, 34.5 at 546 nm, 39.1, 35.3 at 590 nm, 39.2, 36.8 at 650 nm, parallel‐axial extinction. The six strongest lines in the X‐ray powder‐diffraction pattern [d in Å, (I), (hkl)] are: 3.00 (100) (116), 2.80 (50) (205), 2.48. (50) (208), 1.916 (40) (2, 1, 10), 1.765 (60) (220), 1.753 (50) (2, 0, 16). Five chemical analyses carried out, yielding the following results: S 25.76 (25.49–5.97), Fe 10.03 (9.78–10.31), Co 0.78 (0.75–0.81), Ni 12.48 (12.32–12.85), Cu 4.77 (4.69–1.83), Ir 46.98(46.14–17.89), sum 100.80wt%, which produced a formula (Cu1.556Fe0.976)2.532(Ir5.063S10.126)·(Fe2.7451Ni4.404Co0.273)7.422S6.517. The ideal formula is X10Ir5S17.5, which was calculated by single crystal structure analyses, where X = Cu(II) + Fe(II) + Ni(II) + Co(II). The single crystal data were collected using a diffractometer with Mo Kα radiation and a graphite monochromate. The crystal system is trigonal with space group R3m and unit cell parameters a=7.0745(14) Å, c=34.267(10) Å (The superstructure not found), and the final R Indices [with 564 observed reflections, I>2sigma (I)] are R1=0.0495, wR2=0.1349. The specimens are deposited in the Geological Museum of China.
Analysis of Reservoir Forming Conditions and Prediction of Continuous Tight Gas Reservoirs for the Deep Jurassic in the Eastern Kuqa Depression, Tarim Basin
Authors: ZOU Caineng , JIA Jinhua , TAO Shizhen , TAO Xiaowan
Published: October 2011

The exploration targets in the Kuqa Depression at present are mainly structure traps in Cretaceous‐Tertiary. Due to the complexity of mountain distribution and reservoir forming conditions, the exploration of Jurassic in the eastern Kuqa Depression has been in a state of semi‐stagnation since the discovery of the Yinan‐2 gas reservoir. According to the concept and theory of “continuous petroleum reservoirs” and the re‐analysis of the forming conditions of the Yinan‐2 gas reservoir and regional natural gas in the eastern Kuqa Depression, it is believed that the deep Jurassic has good natural gas accumulation conditions as well as geological conditions for forming continuous tight gas reservoirs. The boundary of the Yinan‐2 gas reservoir is not controlled by a structural spillpoint. The downdip part of the structure is dominated by gas, while the hanging wall of the fault is filled by water and forming obvious inverted gas and water. The gas reservoir has the normal temperature and ultrahigh pressure which formed in the near source or inner‐source. All of these characteristics indicate that the Yinan‐2 gas reservoir is different from conventional gas reservoirs. The deep Jurassic in the eastern Kuqa Depression has multisets of source‐reservoir‐cap assemblages, which comprise interbedded sandstones and mudstones. These assemblages are characterized by a self‐generation, self‐preserving and self‐coverage model. Reservoir sandstones and coal measure mudstones are interbedded with each other at a large scale. As the source rocks, Triassic‐Jurassic coal measure mudstones distribute continuously at a large scale and can generate and expel hydrocarbon. Source rocks contact intimately with the overlying sandstone reservoirs. During the late stage of hydrocarbon expulsion, natural gas charged continuously and directly into the neighboring reservoirs. Petroleum migrated mainly in a vertical direction over short distances. With ultra‐high pressure and strong charging intensity, natural gas accumulated continuously. Reservoirs are dominated by sandstones of braided delta facies. The sand bodies distribute continuously horizontal. With low porosity and low permeability, the reservoirs are featured by strong heterogeneity. It is hypothesized that the sandstones of the interior depression tend to be relatively tight with increasing depth and structure stress weakness. Thus, it is predicted that continuous tight gas reservoirs of ultra‐high pressure may exist in the deep formations of the eastern and even the whole Kuqa Depression. So, it is worth evaluating the exploration potential.
Clinical outcome of esophageal varices after hepatic arterial infusion chemotherapy for advanced hepatocellular carcinoma with major portal vein tumor thrombus
Authors: Kodama Hideaki , Aikata Hiroshi , Murakami Eisuke , Miyaki Daisuke , Nagaoki Yuko , Hashimoto Yoshimasa , Azakami Takahiro , Katamura Yoshio , Kawaoka Tomokazu , Takaki Shintaro , Hiramatsu Akira , Waki Koji , Imamura Michio , Kawakami Yoshiiku , Takahashi Shoichi , Ishikawa Masaki , Kakizawa Hideaki , Awai Kazuo , Kenjo Masahiro , Nagata Yasushi , Chayama Kazuaki
Published: October 2011

Aim:  To analyze the clinical outcome of esophageal varices (EV) after hepatic arterial infusion chemotherapy (HAIC) in patients with advanced hepatocellular carcinoma (HCC) and major portal vein tumor thrombus (Vp3/4).

Methods:  The study subjects were 45 consecutive patients who received HAIC for HCC with Vp3/4 between January 2005 and December 2009. HAIC comprised the combination therapy of intra‐arterial 5‐FU with interferon‐α (5‐FU/IFN) in 23 patients and low‐dose cisplatin plus 5‐FU (FP) in 22. Radiotherapy (RT) was also provided in 19 patients for portal vein tumor thrombosis. Aggravation rate for EV and overall survival rate were analyzed.

Results:  The aggravation rates for EV were 47% and 64% at 12 and 24 months, respectively. The survival rates were 47% and 33% at 12 and 24 months, respectively. The response rates to 5‐FU/IFN and FP were 35% and 41%, while the disease control rates in these two groups were 57% and 50%, respectively. There were no significant differences in the objective response and disease control between 5‐FU/IFN and FP. Multivariate analysis identified size of EV (F2/F3) (HR = 7.554, P = 0.006) and HCC disease control (HR = 5.948, P = 0.015) as significant and independent determinants of aggravation of EV, and HCC disease control (HR = 12.233, P < 0.001), metastasis from HCC (HR = 11.469, P = 0.001), ascites (HR = 8.825, P = 0.003) and low serum albumin (HR = 4.953, P = 0.026) as determinants of overall survival. RT for portal vein tumor thrombosis tended to reduce the aggravation rate for EV in patients with these risk factors.

Conclusions:  Hepatocellular carcinoma disease control was the most significant and independent factor for aggravation of EV and overall survival in HCC patients with major portal vein tumor thrombosis treated with HAIC.
Israel–Syria: The Elusive Peace*
Authors: Olmert Josef
Published: October 2011

For 20 years, as of 1991, multiple rounds of negotiations took place between Syria and Israel. These negotiations revolved around the entire gamut of problems separating the two countries: borders, recognition, finality of the conflict, normalization, security arrangements, the Israeli civilian population in the disputed territory, water, Lebanon, the Palestinian issue, Iran, and terrorism. Israeli Prime Ministers, Syrian presidents, foreign ministers, and senior generals from both sides participated in the talks, and third parties such as the United States and Turkey were also involved. Yet peace was not achieved, although not for a lack of effort. This article tries to shed light on some of the reasons for this continuing failure.
Effects of Mesh Density on Static Load Performance of Metal Mesh Gas Foil Bearings
Authors: Lee Yong-Bok , Kim Chang Ho , Kim Tae Ho , Kim Tae Young
Published: October 2011

Metal mesh materials have been used successfully in vibration isolators and bearing dampers due to their superior friction or hysteresis damping mechanism. These materials are formed to metal mesh (or wire mesh) structures in ring-shape by compressing a weave of metal wires, in general. Recently, oil-free rotating machinery implement metal mesh structures into hydrodynamic gas foil bearings by replacing bump strip layers with them, to increase its bearing structural damping. A metal mesh foil bearing (MMFB) consists of a top foil and support elastic metal mesh pads installed between a rotating shaft and a housing. The present research presents load capacity tests of a MMFB at rotor rest (0 rpm) and 30 krpm for three metal mesh densities of 13.1%, 23.2%, and 31.6%. The metal mesh pad of test MMFB is made using a stainless steel wire with a diameter of 0.15 mm. Test rig comprises a rigid rotor with a diameter of 60 mm supported on two ball bearings at both ends and test MMFB with an axial length of 50 mm floats on the rotor. Static loads is provided with a mechanical loading device on test MMFB and a strain gauge type load cell measures the applied static loads. A series of static load versus deflection tests were conducted for selected metal mesh densities at rest (0 rpm). Test data are compared to further test results of static load versus journal eccentricity recorded at the rotor speed of 30 krpm. Test data show a strong nonlinearity of bearing deflection (journal eccentricity) with static load, independent of rotor spinning. Observed hysteresis loops imply significant structural damping of test MMFB. Measured journal deflections at 0 rpm are in similar trend to recorded journal eccentricities at the finite rotor speed; thus implying that the MMFB performance depends mainly on the metal mesh structures. The paper also estimates linearlized stiffness coefficient and damping loss factor of test MMFB using the measured static load versus deflection test data at 0 rpm and 30 krpm. The results show that the highest mesh density of 31.6% produces highest linearlized stiffness coefficient and damping loss factor. With rotor spinning at 30 krpm, the linearlized stiffness coefficient and damping loss factor decrease slightly, independent of metal mesh densities. The present test data will serve as a database for benchmarking MMFB predictive models.
Defined emission area and custom thermal electron sources
Authors: Mackie William A. , Magera Gerald G.
Published: October 2011

The authors report on electron emission defining and stability techniques use for specialized thermionic cathodes. Primarily lanthanum hexaboride and cerium hexaboride have been used for cathode materials but we also use hafnium carbide for cases where background atmospheres preclude the use of hexaborides. A common form of emission suppression is to embed an oriented single crystal in graphite to suppress side emission and to help shape the electric field. Single planar discs 50 μm in diameter have been tested for use as high brightness, stable, and long life thermal sources. Line sources have also been developed with linewidth/lengths to 10/500 μm. Emission tests performed have shown that long-term drift and short-term instabilities can originate from boride and carbon interactions respectively. Improved mounting techniques are shown to yield emission with short-term beam current stability <0.05%.
The Complex Folding Network of Single Calmodulin Molecules
Authors: Stigler Johannes , Ziegler Fabian , Gieseke Anja , Gebhardt J. Christof M. , Rief Matthias
Published: October 2011

A multidimensional folding pathway can be observed online in single-molecule experiments.
China's Science Funding
Authors: Zare Richard N. , Winnacker Ernst-Ludwig
Published: October 2011

This year marks the 25th anniversary of the National Natural Science Foundation of China (NSFC), the largest funding agency for basic research in the country. On this occasion, the leadership of the NSFC and the Chinese Ministry of Finance arranged for the NSFC to be reviewed by an International Evaluation Committee (IEC), which sets a new precedent for China. Part of the motivation for this review was a desire on the part of the Chinese government to determine how well their extensive efforts to boost the support of scientific research measure up to international standards. Apart from logistical arrangements, the IEC was completely independent in its operations. An “evidence-based review” (that is, an overview with extensive data) was carefully prepared by China's National Center for Science and Technology Evaluation. We were also given access to anyone with whom we wanted to speak, including those critical of the present Chinese research culture. Both the evidence-based review and the full report, with our comments and recommendations, are accessible online (
www.nsfc.gov.cn/english/13rp/index.html
). The process and results of this report should be useful not only for China but also for many other nations striving to produce a merit-based culture for science.
Ralph M. Steinman (1943–2011)
Authors: Mellman Ira , Nussenzweig Michel
Published: October 2011

An immunologist's dedication, courage, and influential discoveries affected research far beyond the work for which he received the 2011 Nobel Prize.
Mediation of Host Immune Responses after Immunization of Neonatal Calves with a Heat-Killed Mycobacterium avium subsp. paratuberculosis Vaccine
Authors: Stabel J. R. , Waters W. R. , Bannantine J. P. , Lyashchenko K.
Published: October 2011

A major drawback of current whole-cell vaccines for
Mycobacterium avium
subsp.
paratuberculosis
is the interference with diagnostic tests for bovine tuberculosis (TB) and paratuberculosis. The current study was designed to explore the effects of immunization with a heat-killed whole-cell vaccine (Mycopar) on diagnostic test performance and to characterize host immune responses to vaccination over a 12-month period. Neonatal dairy calves were assigned to treatment groups consisting of (i) controls, not vaccinated (
n
= 5), and (ii) vaccinates, vaccinated with Mycopar vaccine (
n
= 5). The results from this study demonstrated a rapid initiation of
M. avium
subsp.
paratuberculosis
-specific gamma interferon (IFN-γ) in vaccinated calves by 7 days, with robust responses throughout the study. Vaccinated calves also had responses to
M. bovis
purified protein derivative tuberculin (BoPPD) but minimal reactivity to ESAT-6/CFP-10, an
M. bovis
recombinant fusion protein. The levels of antigen-specific interleukin-4 (IL-4) and IL-10 were markedly decreased in vaccinated calves between days 7 and 90 of the study but thereafter were similar to the levels in controls. Vaccinated calves began to seroconvert at 4 months, with 4/5 calves having detectable
M. avium
subsp.
paratuberculosis
antibody by 6 months. The responses in test platforms for bovine TB were negligible in the vaccinate group, as only one calf had a response, which was in the suspect range of the comparative cervical skin test. Serum antibody responses to
M. bovis
antigens ESAT-6, CFP-10, and MPB83 were negative on the Vet TB STAT-PAK, DPP VetTB, and DPP BovidTB tests. These results suggest that the Mycopar vaccine will interfere with diagnostic tools for paratuberculosis but result in low interference with the comparative cervical skin test and emerging serologic tests for
M. bovis
.
Macromolecular Assembly-Driven Processing of the 2/3 Cleavage Site in the Alphavirus Replicase Polyprotein
Authors: Lulla Aleksei , Lulla Valeria , Merits Andres
Published: October 2011

Semliki Forest virus (SFV) is a member of the
Alphavirus
genus, which produces its replicase proteins in the form of a nonstructural (ns) polyprotein precursor P1234. The maturation of the replicase occurs in a temporally controlled manner by protease activity of nsP2. The template preference and enzymatic capabilities of the alphaviral replication complex have a very important connection with its composition, which is irreversibly altered by proteolysis. The final cleavage of the 2/3 site in the ns polyprotein apparently leads to significant rearrangements within the replication complex and thus denotes the “point of no return” for viral replication progression. Numerous studies have devised rules for when and how ns protease acts, but how the alphaviral 2/3 site is recognized remained largely unexplained. In contrast to the other two cleavage sites within the ns polyprotein, the 2/3 site evidently lacks primary sequence elements in the vicinity of the scissile bond sufficient for specific protease recognition. In this study, we sought to investigate the molecular details of the regulation of the 2/3 site processing in the SFV ns polyprotein. We present evidence that correct macromolecular assembly, presumably strengthened by exosite interactions rather than the functionality of the individual nsP2 protease, is the driving force for specific substrate targeting. We conclude that structural elements within the macrodomain of nsP3 are used for precise positioning of a substrate recognition sequence at the catalytic center of the protease and that this process is coordinated by the exact N-terminal end of nsP2, thus representing a unique regulation mechanism used by alphaviruses.
Mutational Mapping of pUL131A of Human Cytomegalovirus Emphasizes Its Central Role for Endothelial Cell Tropism
Authors: Schuessler Andrea , Sampaio Kerstin Laib , Straschewski Sarah , Sinzger Christian
Published: October 2011

The UL131A protein is part of a pentameric variant of the gcIII complex in the virion envelope of human cytomegalovirus (HCMV), which has been found essential for efficient entry into endothelial cells (ECs). Using a systematic mutational scanning approach, we aimed to define peptide motifs within the UL131A protein that contribute to EC infection. Mutant viruses were generated in which charged amino acids within frames of 2 to 6 amino acids were replaced with alanines. The resulting viruses were evaluated with regard to their potential to infect EC cultures. Four clusters of charged amino acids essential for EC infection were identified (amino acids 22 to 27, 32 to 35, 64 to 69, and 116 to 121). Mutations of individual charge clusters within amino acids 72 to 104 caused minor reductions of EC tropism, but these effects were additive in a combined mutation, showing that this region also contributes to EC tropism. Only charge clusters within amino acids 46 to 58 were found irrelevant for EC infection. In conclusion, the unusual sensitivity to mutations, together with the remarkable conservation of the UL131A protein, emphasizes its particular role for EC tropism of HCMV.
Important but Differential Roles for Actin in Trafficking of Epstein-Barr Virus in B Cells and Epithelial Cells
Authors: Valencia Sarah M. , Hutt-Fletcher Lindsey M.
Published: October 2011

Epstein-Barr virus (EBV) uses different virus and cell proteins to enter its two major targets, B lymphocytes and epithelial cells. The routes that the virus takes into the two cell types are also different. To determine if these differences extend to movement from the cell surface to the nucleus, we examined the fate of incoming virus. Essentially all virus that entered a B cell remained stable for at least 8 h. In contrast, up to 80% of virus entering an epithelial cell was degraded in a compartment sensitive to inhibitors of components involved in autophagy. Inhibitors of actin remodeling blocked entry into a B cell but had no effect or enhanced entry into an epithelial cell. Inhibitors of the microtubule network reduced intracellular transport in both cell types, but movement to the nucleus in an epithelial cell also required involvement of the actin cytoskeleton. Deletion of the cytoplasmic tail of CR2, which in an epithelial cell interacts with the actin nucleator FHOS/FHOD when cross-linked by EBV, had no effect on infection. However, inhibitors of downstream signaling by integrins reduced intracellular transport. Cooperation of the microtubule and actin cytoskeletons, possibly activated by interaction with integrin binding proteins in the envelope of EBV, is needed for successful infection of an epithelial cell.
Pestivirus Virion Morphogenesis in the Absence of Uncleaved Nonstructural Protein 2-3
Authors: Lattwein E. , Klemens O. , Schwindt S. , Becher P. , Tautz N.
Published: October 2011

The familyFlaviviridaecontains three genera of positive-strand RNA viruses, namely,Flavivirus,Hepacivirus(e.g., hepatitis C virus [HCV]), andPestivirus. Pestiviruses, like bovine viral diarrhea virus (BVDV), bear a striking degree of similarity to HCV concerning polyprotein organization, processing, and function. Along this line, in both systems, release of nonstructural protein 3 (NS3) is essential for viral RNA replication. However, both viruses differ significantly with respect to processing efficiency at the NS2/3 cleavage site and abundance as well as functional relevance of uncleaved NS2-3. In BVDV-infected cells, significant amounts of NS2-3 accumulate at late time points postinfection and play an essential but ill-defined role in the production of infectious virions. In contrast, complete cleavage of the HCV NS2-3 counterpart has been reported, and unprocessed NS2-3 is not required throughout the life cycle of HCV, at least in cell culture. Here we describe the selection and characterization of the first pestiviral genome with the capability to complete productive infection in the absence of uncleaved NS2-3. Despite the insertion of a ubiquitin gene or an internal ribosomal entry site between the NS2 and NS3 coding sequences, the selected chimeric BVDV-1 genomes gave rise to infectious virus progeny. In this context, a mutation in the N-terminal third of NS2 was identified as a critical determinant for efficient production of infectious virions in the absence of uncleaved NS2-3. These findings challenge a previously accepted dogma for pestivirus replication and provide new implications for virion morphogenesis of pestiviruses and HCV.
Ligand-Bound Structures of the Dengue Virus Protease Reveal the Active Conformation
Authors: Noble Christian G. , Seh Cheah Chen , Chao Alexander T. , Shi Pei Yong
Published: October 2011

Dengue is a mosquito-borne viral hemorrhagic disease that is a major threat to human health in tropical and subtropical regions. Here we report crystal structures of a peptide covalently bound to dengue virus serotype 3 (DENV-3) protease as well as the serine-protease inhibitor aprotinin bound to the same enzyme. These structures reveal, for the first time, a catalytically active, closed conformation of the DENV protease. In the presence of the peptide, the DENV-3 protease forms the closed conformation in which the hydrophilic β-hairpin region of NS2B wraps around the NS3 protease core, in a manner analogous to the structure of West Nile virus (WNV) protease. Our results confirm that flavivirus proteases form the closed conformation during proteolysis, as previously proposed for WNV. The current DENV-3 protease structures reveal the detailed interactions at the P4′ to P3 sites of the substrate. The new structural information explains the sequence preference, particularly for long basic residues in the nonprime side, as well as the difference in substrate specificity between the WNV and DENV proteases at the prime side. Structural analysis of the DENV-3 protease-peptide complex revealed a pocket that is formed by residues from NS2B and NS3; this pocket also exists in the WNV NS2B/NS3 protease structure and could be targeted for potential antivirus development. The structural information presented in the current study is invaluable for the design of specific inhibitors of DENV protease.
The Lytic Phase of Epstein-Barr Virus Requires a Viral Genome with 5-Methylcytosine Residues in CpG Sites
Authors: Kalla Markus , Göbel Christine , Hammerschmidt Wolfgang
Published: October 2011

Epstein-Barr virus (EBV) is a human herpesvirus which has been studied intensively for its role in certain human tumors. It also serves as a model of herpesviral latency because it establishes an immediate, latent infection in human B cells. When EBV infects quiescent, primary B cells it induces their continuous proliferation to yield growth-transformed B-cell lines
in vitro
. The lytic or productive phase of EBV's life cycle is induced by the expression of the viral
BZLF1
gene in latently infected cells. The BZLF1 protein is a transactivator, which selectively binds to two classes of distinct DNA sequence motifs. One class is similar to the motifs that are bound by members of the AP-1 transcription factor family to which BZLF1 belongs. The second class, which contains CpG motifs, is predominant in viral promoters of early lytic genes and is BZLF1's preferred or exclusive target sequence when methylated. The
BZLF1
gene is transiently expressed in newly infected B cells but fails to induce EBV's lytic cycle, potentially because the virion DNA is unmethylated. Here we report that the lack of 5-methylcytosine residues in CpG sites of virion DNA prevents the expression of essential lytic genes indispensable for viral DNA amplification during productive infection. This finding indicates that BZLF1 transactivates these promoters in a methylation-dependent fashion and explains how progeny virus synthesis is abrogated in newly infected B cells. Our data also reveal that viral lytic DNA synthesis precludes CpG methylation of virion DNA during EBV's lytic, productive cycle, which can be overcome by the ectopic expression of a prokaryotic cytosine methyltransferase to yield CpG-methylated virion DNA. Upon infection of B cells, randomly CpG-methylated virion DNA induces high expression of essential lytic genes in contrast to virion DNA free of 5-methylcytosine residues. Our data suggest that unmethylated virion DNA is part of EBV's strategy to prevent the viral lytic phase in newly infected B cells, allowing it to establish its characteristic latent infection in them.
Engineering, Expression, Purification, and Characterization of Stable Clade A/B Recombinant Soluble Heterotrimeric gp140 Proteins
Authors: Sellhorn George , Kraft Zane , Caldwell Zachary , Ellingson Katharine , Mineart Christine , Seaman Michael S. , Montefiori David C. , Lagerquist Eliza , Stamatatos Leonidas
Published: October 2011

The envelope glycoprotein (Env) of human immunodeficiency virus type 1 (HIV-1) is composed of two noncovalently associated subunits: an extracellular subunit (gp120) and a transmembrane subunit (gp41). The functional unit of Env on the surface of infectious virions is a trimer of gp120/gp41 heterodimers. Env is the target of anti-HIV neutralizing antibodies. A considerable effort has been invested in the engineering of recombinant soluble forms of the virion-associated Env trimer as vaccine candidates to elicit anti-HIV neutralizing antibody responses. These soluble constructs contain three gp120 subunits and the extracellular segments of the corresponding gp41 subunits. The individual gp120/gp41 protomers on these soluble trimers are identical in amino acid sequence (homotrimers). Here, we engineered novel soluble trimeric gp140 proteins that are formed by the association of gp140 protomers that differ in amino acid sequence and glycosylation patterns (heterotrimers). Specifically, we engineered soluble heterotrimeric proteins composed of clade A and clade B Env protomers. The clade A gp140 protomers were derived from viruses isolated during acute infection (Q168a2, Q259d2.17, and Q461e2), whereas the clade B gp140 protomers were derived from a virus isolated during chronic infection (SF162). The amino acid sequence divergence between the clade A and the clade B Envs is approximately 24%. Neutralization epitopes in the CD4 binding sites and coreceptor binding sites, as well as the membrane-proximal external region (MPER), were differentially expressed on the heterotrimeric and homotrimeric proteins. The heterotrimeric gp140s elicited broader anti-tier 1 isolate neutralizing antibody responses than did the homotrimeric gp140s.
The Hepatitis B Virus X Protein Elevates Cytosolic Calcium Signals by Modulating Mitochondrial Calcium Uptake
Authors: Yang Bei , Bouchard Michael J.
Published: October 2011

Chronic hepatitis B virus (HBV) infections are associated with the development of hepatocellular carcinoma (HCC). The HBV X protein (HBx) is thought to play an important role in the development of HBV-associated HCC. One fundamental HBx function is elevation of cytosolic calcium signals; this HBx activity has been linked to HBx stimulation of cell proliferation and transcription pathways, as well as HBV replication. Exactly how HBx elevates cytosolic calcium signals is not clear. The studies described here show that HBx stimulates calcium entry into cells, resulting in an increased plateau level of inositol 1,4,5-triphosphate (IP3)-linked calcium signals. This increased calcium plateau can be inhibited by blocking mitochondrial calcium uptake and store-operated calcium entry (SOCE). Blocking SOCE also reduced HBV replication. Finally, these studies also demonstrate that there is increased mitochondrial calcium uptake in HBx-expressing cells. Cumulatively, these studies suggest that HBx can increase mitochondrial calcium uptake and promote increased SOCE to sustain higher cytosolic calcium and stimulate HBV replication.
Mechanism of hydration and isomerisation of 4-ethylidene-2,6-di-tert-butyl-2,5-cyclohexadien-1-one. Kinetics, acid-base catalysis and solvent deuterium isotope effects
Authors: Velek Jiří , Koutek Bohumír , Souček Milan
Published: October 2011

Competitive hydration and isomerisation of the quinone methide I at 25 °C in an aqueous medium in the region of pH 2.4-13.0 was studied spectrophotometrically. The only reaction products in the studied range of pH are 4-hydroxybenzyl alcohol (II) and 4-hydroxystyrene (III). The form of the overall rate equation corresponds to a general acid-base catalysis. The mechanism of both reactions for three markedly separated pH regions is discussed on the basis of kinetic data and solvent deuterium effect.
Effect of polymerization degree of oligogalacturonates and D-galacturonans on their circular dichroic spectra
Authors: Bystrický Slavomír , Kohn Rudolf , Sticzay Tibor
Published: October 2011

The CD spectra of aqueous solutions of homopolymeric sodium oligogalacturonates and D-galacturonans of polymerization degree n = 1-64, as well as lower calcium oligogalacturonates (n = 1-5) were measured. Chiroptic properties were correlated with the polymerization degree in terms of optical superposition of monomeric unit increments. Interpretation of obtained data, respecting further physicochemical properties entitles to conclude that the conformation of macromolecules of D-galacturonan in solution is close to helical structure.
Reduction of some mesyloxy and tosyloxy steroids with sodium iodide and zinc dust
Authors: Kočovský Pavel , Černý Václav
Published: October 2011

Reduction of primary and secondary steroidal alcohols via their mesylates and tosylates with sodium iodide and zinc dust in 1,2-dimethoxyethane is shown to be a mild and simple preparative method for removing the hydroxyl from polyfunctional compounds. It may be successfully applied to substances with an isolated double bond, a keto group, a α-hydroxyketo, α,α'-dihydroxyketo, or α,β-unsaturated keto grouping, an isolated tertiary hydroxyl, an epoxide ring or a nitrile group. All these functions are not affected.
Measurements of the excess volume of benzene-methanol, benzene-acetonitrile and methanol-acetonitrile mixtures by a vibrating-tube densimeter
Authors: Cibulka Ivan , Hynek Vladimír , Holub Robert , Pick Jiří
Published: October 2011

A digital vibrating-tube densimeter was constructed for measuring the density of liquids at several temperatures. The underlying principle of the apparatus is the measurement of the period of eigen-vibrations of a V-shaped tube; the second power of the period of the vibrations is proportional to the density of the liquid in the tube. The temperature of the measuring system is controlled by an electronic regulator. The mean error in the density measurement is approximately ±1 . 10-5 g cm-3 at 25 °C and ±2 . 10-5 g cm-3 at 40 °C. The apparatus was used for an indirect measurement of the excess volume, tested with the benzene-cyclohexane system and further used for determining the excess volume of the benzene-methanol, benzene-acetonitrile and methanol-acetonitrile systems at 25 and 40 °C.
Heats of vaporization of nonelectrolytes
Authors: Kyselka Petr , Rameš Jiří , Procházka Karel
Published: October 2011

The first-order perturbation theory of liquids was used for developing an approximate expression suitable for a rapid calculation of the heat of vaporization of nonpolar liquids formed by approximately spherical molecules. The calculation uses only available physico-chemical properties of substances, namely the critical data. The results are tested by a comparison with existing experimental data on a series of nonpolar substances. The agreement between calculated values and experimental data is relatively good. The maximum deviation between theoretical and experimental values does not exceed ±10%.
Heats of mixing of nonelectrolytes
Authors: Rameš Jiří , Kyselka Petr , Procházka Karel
Published: October 2011

The first-order perturbation method is applied to a rapid estimation of heats of mixing of binary liquid mixtures containing molecules with a negligible polarity and approximately spherical symmetry. The calculation is based on the approximate perturbation expansion of the Helmholtz free energy up to first order and requires the knowledge of the radial distribution function of the hard-sphere reference system at the contact point. Generalized relations are used for estimating the molecular parameters. The calculated values are compared with experimental data on six mixtures. Good qualitative agreement was achieved in all cases investigated.
Concentration in a suspension discharging from a mixed vessel
Authors: Řeháková Milada , Rod Vladimír
Published: October 2011

Theoretical model has been proposed for the calculation of concentration of a suspension discharging at the top from a mixed vessel. It has been assumed that no separation of solids occurs during sampling near the level and that the samples provide local values of concentration obeying the diffusional model. The model has been tested on experiments involving a cylindrical vessel with baffles mixed by a propeller impeller.