The feasibility of K XRF bone lead measurements in mice assessed using 3D-printed phantoms

This article describes the development of a system forin vivomeasurements of lead body burden in mice using109Cd K x-ray fluorescence (XRF). This K XRF system could facilitate early-stage studies on interventions that ameliorate or reverse organ tissue damage from lead poisoning by reducing animal numbers through a cross-sectional study approach. A novel mouse phantom was developed based on a mouse atlas and 3D-printed using PLA plastic with plaster of Paris 'bone' inserts. PLA plastic was found to be a good surrogate for soft tissue in XRF measurements and the phantoms were found to be good models of mice. As expected, lead detection limits varied with mouse size, mouse orientation, and mouse position with respect to the source and detector. The work suggests that detection limits of 10 to 20μg Pb per g bone mineral may be possible for a 2 to 3 hour XRF measurement in a single animal, an adequate limit for some pre-clinical studies. The109Cd K XRF mouse measurement system was also modeled using the Monte Carlo code MCNP. The combination of experiment and modeling found that contrary to expectation, accurate measurements of lead levels in mice required calibration using mouse-specific calibration standards due to the coherent scatter peak normalization failing when small animals are measured. MCNP modeling determined that this was because the coherent scatter signal from soft tissue, which until now has been assumed negligible, becomes significant when compared to the coherent scatter signal in bone in small animals. This may have implications for some human measurements. This work suggests that109Cd K x-ray fluorescence measurements of lead body burden are precise enough to make the system feasible for small animals if appropriately calibrated. Further work to validate the technology's measurement accuracy and performancein vivowill be required.

Alloimmunization in dogs after transfusion: A serial cross-match study

BACKGROUND

Cross-matching is performed to determine the serological compatibility of donor and recipient blood. Current guidelines recommend that cross-matching should be performed in dogs when an initial transfusion was performed more than 4 days ago or when the transfusion history is unknown.

HYPOTHESIS

Determination at what time point alloantibodies are detected in dogs after transfusion. The hypothesis was that dogs would form alloantibodies within 4 days after a transfusion.

ANIMALS

Twenty-one anemic dogs were transfused and monitored for at least 4 subsequent days. Exclusion criteria were persistent red blood cell (RBC) agglutination and a previous transfusion.

METHODS

Prospective observational study. Cross-matching was performed before the initial DEA 1-compatible transfusion and on days 1, 2, 3, and 4 and if possible, between day 5 and 28, using the tube method without enhancement (major cross-match, recipient controls); recipients were monitored for transfusion reactions.

RESULTS

In 12/21 dogs a positive cross-match (microscopic degree of agglutination [AD] 1+ to 2+) was observed within 4 days after the transfusion. In a nonlinear regression model, no significant association was detected between type of anemia (P = .41), RBC storage time (P = .44), immunosuppressive treatment (P = .75) nor transfusion volume (P = .70) and the occurrence of positive cross-matches within 4 days after transfusion. Another 4 dogs developed a positive cross-match (microscopic AD 1+ to 2+) after 6 to 13 days.

CONCLUSIONS AND CLINICAL IMPORTANCE

Because production of alloantibodies was detected as early as 1 day after transfusion, cross-matching should be performed before every subsequent transfusion.

Maternal and neonatal outcome after vaginal breech delivery at term after cesarean section - a prospective cohort study of the Frankfurt breech at term cohort (FRABAT)

OBJECTIVE

To compare the neonatal and maternal outcomes as well as the mode of delivery of intended vaginal breech deliveries in women with a prior cesarean section to primiparous patients.

STUDY DESIGN

The prospective monocenter cohort study was conducted among 604 women who presented for an intended vaginal singleton breech delivery at term between January 2007 and December 2016.

RESULTS

Out of 37 women with a prior cesarean 19 had a successful vaginal delivery. 344 of 567 primiparous women had a successful vaginal delivery. Neonatal morbidity and mortality as well as maternal outcome were not significantly different in successful vaginal deliveries of women with prior cesarean compared to primiparous patients. The cesarean section rate was not significantly higher in the group of women with a prior cesarean (49%) compared to the group of primipara (39%).

CONCLUSION

A prior cesarean should not be taken as an exclusion criterion for a planned vaginal delivery out of a breech presentation at term. Large multicenter, case-controlled studies are necessary to implement international guidelines.

[S3 guidelines on the diagnosis and treatment of carcinoma of the endometrium : Requirements for pathology]

The present article summarises the relevant aspects of the S3 guidelines on endometrioid carcinomas. The recommendations include the processing rules of fractional currettings as well as for hysterectomy specimens and lymph node resections (including sentinel lymph nodes). Besides practical aspects, the guidelines consider the needs of the clinicians for appropriate surgical and radiotherapeutic treatment of the patients. Carcinosarcomas are assigned to the endometrial carcinoma as a special variant. For the first time, an algorithmic approach for evaluation of the tumour tissue for Lynch syndrome is given. Prognostic factors based on morphologic findings are summarised.

Investigation of direct counting and sizing of DNA fragments in flow applying an improved data analysis and correction method

Direct detection of single stained DNA fragments in flow is a very sensitive method for nucleic acid detection which does not need any amplification process. We have developed an instrument for direct counting and sizing of single DNA fragments (single or double stranded DNA) in flow with integrated sample volume measurement for concentration determination. As the method is a potential reference method for DNA quantification, processes affecting the measurement uncertainty are of major interest. Additionally, comparison of this method to the orthogonal method of digital PCR is useful with the restriction of low specificity of the direct detection method. In this study, we analysed raw detector signals and the sizing performance for target identification and the effect of coincidence detection concerning concentration measurements. We present data of purified artificial DNA samples measured with the home-built setup. Main emphasis was to develop an improved data analysis method to gain insight into and carefully correct for coincident detection of DNA fragments and for estimation of the amount of fragment dimers.

Prevalence of WNT10A gene mutations in non-syndromic oligodontia

OBJECTIVES

Non-syndromic oligodontia is an infrequent clinical condition whose etiology is not yet completely understood being a wide spectrum of gene mutations described in concomitance with this severe form of tooth agenesis. Recently, multiple observations have linked up to 50% of cases with isolated hypodontia to mutations in the WNT10A gene. Here, we hypothesized that mutations in the WNT10A gene could also be present in families affected by non-syndromic oligodontia.

MATERIAL AND METHODS

All available patients with non-syndromic oligodontia (n = 20) treated at the Department of Orthodontics, University of Giessen, Germany between 1986 and 2013 as well as their family members were analyzed for mutations in the WNT10A gene.

RESULTS

Mutation screening was positive in 50% of the 20 patients. The analysis revealed that the mutations 2:219755011(c.682T>TA)(p.F228I), 2:219754822(c.493G>GA)(p.G165R), 2:219754816(c.487C>CT)(p.R163W), and 2:219747090(c.321C>CA)(p.C107*), the novel missense mutation 2:219757676(c.937G/GT)(p.G313C), and the novel synonym variant 2:219754854(c.525C>CT)(p.H175H) were present.

CONCLUSION

Multiple phenotypes are found in individuals presenting mutations in the WNT10A gene. Among them, the stop codon p.C107* as well as the biallelic p.F228I variants correlate with the most severe oligodontia phenotypes. In addition, we diagnosed the monoallelic mutations p.F228I, p.G165R, and p.G313C in healthy relatives with normal dentitions.

CLINICAL RELEVANCE

A correct diagnosis of non-syndromic oligodontia is fundamental to discard a possible underlying pathology in which multiple tooth agenesis could be the most evidential clinical sign. Due to the wide spectrum of pathologies that are associated to mutations in the WNT10A gene, an extended genetic analysis of these individuals' relatives is also essential.

Label-free whole blood cell differentiation based on multiple frequency AC impedance and light scattering analysis in a micro flow cytometer

We developed a microfluidic sensor for label-free flow cytometric cell differentiation by combined multiple AC electrical impedance and light scattering analysis. The measured signals are correlated to cell volume, membrane capacity and optical properties of single cells. For an improved signal to noise ratio, the microfluidic sensor incorporates two electrode pairs for differential impedance detection. One-dimensional sheath flow focusing was implemented, which allows single particle analysis at kHz count rates. Various monodisperse particles and differentiation of leukocytes in haemolysed samples served to benchmark the microdevice applying combined AC impedance and side scatter analyses. In what follows, we demonstrate that AC impedance measurements at selected frequencies allow label-free discrimination of platelets, erythrocytes, monocytes, granulocytes and lymphocytes in whole blood samples involving dilution only. Immunofluorescence staining was applied to validate the results of the label-free cell analysis. Reliable differentiation and enumeration of cells in whole blood by AC impedance detection have the potential to support medical diagnosis for patients with haemolysis resistant erythrocytes or abnormally sensitive leucocytes, i.e. for patients suffering from anaemia or leukaemia.

Three months of weekly rifapentine plus isoniazid is less hepatotoxic than nine months of daily isoniazid for LTBI

SETTING

Nine months of daily isoniazid (9H) and 3 months of once-weekly rifapentine plus isoniazid (3HP) are recommended treatments for latent tuberculous infection (LTBI). The risk profile for 3HP and the contribution of hepatitis C virus (HCV) infection to hepatotoxicity are unclear.

OBJECTIVES

To evaluate the hepatotoxicity risk associated with 3HP compared to 9H, and factors associated with hepatotoxicity.

DESIGN

Hepatotoxicity was defined as aspartate aminotransferase (AST) >3 times the upper limit of normal (ULN) with symptoms (nausea, vomiting, jaundice, or fatigue), or AST >5 x ULN. We analyzed risk factors among adults who took at least 1 dose of their assigned treatment. A nested case-control study assessed the role of HCV.

RESULTS

Of 6862 participants, 77 (1.1%) developed hepatotoxicity; 52 (0.8%) were symptomatic; 1.8% (61/3317) were on 9H and 0.4% (15/3545) were on 3HP (P < 0.0001). Risk factors for hepatotoxicity were age, female sex, white race, non-Hispanic ethnicity, decreased body mass index, elevated baseline AST, and 9H. In the case-control study, HCV infection was associated with hepatotoxicity when controlling for other factors.

CONCLUSION

The risk of hepatotoxicity during LTBI treatment with 3HP was lower than the risk with 9H. HCV and elevated baseline AST were risk factors for hepatotoxicity. For persons with these risk factors, 3HP may be preferred.

Intermittent tuberculosis treatment for patients with isoniazid intolerance or drug resistance

SETTING

Twenty tuberculosis (TB) clinics in the United States and Canada.

OBJECTIVE

To evaluate the efficacy and safety of a 6-month intermittent regimen of rifampin (RMP), pyrazinamide (PZA) and ethambutol (EMB) in human immunodeficiency virus (HIV) negative patients with culture-confirmed pulmonary or extra-pulmonary tuberculosis and either isoniazid (INH) resistance or INH intolerance.

DESIGN

Patients were enrolled in a single-arm clinical trial to receive intermittent dosing after at least 14 initial daily doses of RMP+PZA+EMB. Treatment was continued twice (BIW) or thrice weekly (TIW) per physician/patient preference for a total of 6 months, with 2 years of follow-up for relapse after treatment.

RESULTS

From 1999 to 2004, 98 patients were enrolled, 78 with reported INH resistance and 20 with INH intolerance. BIW dosing was used in 77 and TIW in 21. Study treatment was completed in 73 (74%). Reasons for discontinuation were hepatic adverse events (n= 12), other adverse effects (n= 3) and other reasons (n= 10). Failure (n= 1) and relapse (n= 2) occurred in 3 (3.5%, 95%CI 1.2-9.8) of 86 patients eligible for efficacy analysis, all occurring in patients with cavitary, acid-fast bacilli smear-positive pulmonary TB.

CONCLUSIONS

Intermittent RMP+PZA+EMB appears to be effective in HIV-negative patients, but the regimen is poorly tolerated, possibly due to the prolonged use of PZA. Alternative regimens of lower toxicity are needed.

Measurement of inelastic, single- and double-diffraction cross sections in proton-proton collisions at the LHC with ALICE

Measurements of cross sections of inelastic and diffractive processes in proton-proton collisions at LHC energies were carried out with the ALICE detector. The fractions of diffractive processes in inelastic collisions were determined from a study of gaps in charged particle pseudorapidity distributions: for single diffraction (diffractive mass MX <200 GeV/c2) [Formula: see text], and [Formula: see text], respectively at centre-of-mass energies [Formula: see text]; for double diffraction (for a pseudorapidity gap Δη>3) σDD/σINEL=0.11±0.03,0.12±0.05, and [Formula: see text], respectively at [Formula: see text]. To measure the inelastic cross section, beam properties were determined with van der Meer scans, and, using a simulation of diffraction adjusted to data, the following values were obtained: [Formula: see text] mb at [Formula: see text] and [Formula: see text] at [Formula: see text]. The single- and double-diffractive cross sections were calculated combining relative rates of diffraction with inelastic cross sections. The results are compared to previous measurements at proton-antiproton and proton-proton colliders at lower energies, to measurements by other experiments at the LHC, and to theoretical models.

Net-charge fluctuations in Pb-Pb collisions at sqrt[sNN]=2.76 TeV

We report the first measurement of the net-charge fluctuations in Pb-Pb collisions at sqrt[sNN]=2.76  TeV, measured with the ALICE detector at the CERN Large Hadron Collider. The dynamical fluctuations per unit entropy are observed to decrease when going from peripheral to central collisions. An additional reduction in the amount of fluctuations is seen in comparison to the results from lower energies. We examine the dependence of fluctuations on the pseudorapidity interval, which may account for the dilution of fluctuations during the evolution of the system. We find that the fluctuations at the LHC are smaller compared to the measurements at the BNL Relativistic Heavy Ion Collider, and as such, closer to what has been theoretically predicted for the formation of a quark-gluon plasma.

Charge separation relative to the reaction plane in Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV

Measurements of charge-dependent azimuthal correlations with the ALICE detector at the LHC are reported for Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV. Two- and three-particle charge-dependent azimuthal correlations in the pseudorapidity range |η| < 0.8 are presented as a function of the collision centrality, particle separation in pseudorapidity, and transverse momentum. A clear signal compatible with a charge-dependent separation relative to the reaction plane is observed, which shows little or no collision energy dependence when compared to measurements at RHIC energies. This provides a new insight for understanding the nature of the charge-dependent azimuthal correlations observed at RHIC and LHC energies.

Pion, kaon, and proton production in central Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV

In this Letter we report the first results on π(±), K(±), p, and p production at midrapidity (|y|<0.5) in central Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV, measured by the ALICE experiment at the LHC. The p(T) distributions and yields are compared to previous results at sqrt[s(NN)] = 200 GeV and expectations from hydrodynamic and thermal models. The spectral shapes indicate a strong increase of the radial flow velocity with sqrt[s(NN)], which in hydrodynamic models is expected as a consequence of the increasing particle density. While the K/π ratio is in line with predictions from the thermal model, the p/π ratio is found to be lower by a factor of about 1.5. This deviation from thermal model expectations is still to be understood.

Measurement of the cross section for electromagnetic dissociation with neutron emission in Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV

The first measurement of neutron emission in electromagnetic dissociation of ^{208}Pb nuclei at the LHC is presented. The measurement is performed using the neutron zero degree calorimeters of the ALICE experiment, which detect neutral particles close to beam rapidity. The measured cross sections of single and mutual electromagnetic dissociation of Pb nuclei at sqrt[s(NN)]=2.76 TeV with neutron emission are σ(singleEMD)=187.4 ± 0.2(stat)(-11.2)(+13.2) (syst) b and σ(mutualEMD) = 5.7 ± 0.1(stat) ± 0.4(syst) b, respectively. The experimental results are compared to the predictions from a relativistic electromagnetic dissociation model.

Quantitative assessment of cell viability based on flow cytometry and microscopy

We compare flow cytometric and microscopic determination of cell viability by fluorescence labeling using calcein acetoxy-methyl-ester and ethidium homodimer-1 as live and dead stain, respectively. Peripheral blood monocytes served as model system and were accumulated applying density gradients. Subsequently, monocytes were further enriched by magnetic-activated or fluorescence-activated cell sorting (MACS, FACS) targeting the antigen CD14. Identical samples were used for flow cytometric and microscopic analysis to allow direct comparison of both analysis methods. More than 1,000 cells were measured for each sample to minimize the measurement uncertainty caused by counting statistics. We observed good agreement of flow cytometric and microscopic viability measurements. On average, the difference in viability measured by flow cytometry and microscopy amounted to (2.7 ± 1.4)% for live staining and (1.7 ± 1.2)% for dead staining. These deviations were similar to the uncertainty of measurement for cell viability, thus demonstrating that both methods delivered equal results. Besides monocytes, comparison of flow cytometric and microscopy viability for MACS enriched CD34-positive cells also showed consistent results.

Production of muons from heavy flavor decays at forward rapidity in pp and Pb-Pb collisions at sqrt[s(NN)]=2.76 TeV

The ALICE Collaboration has measured the inclusive production of muons from heavy-flavor decays at forward rapidity, 2.5<y<4, in pp and Pb-Pb collisions at sqrt[s(NN)]=2.76  TeV. The p(t)-differential inclusive cross section of muons from heavy-flavor decays in pp collisions is compared to perturbative QCD calculations. The nuclear modification factor is studied as a function of p(t) and collision centrality. A weak suppression is measured in peripheral collisions. In the most central collisions, a suppression of a factor of about 3-4 is observed in 6<p(t)<10  GeV/c. The suppression shows no significant p(t) dependence.

J/ψ suppression at forward rapidity in Pb-Pb collisions at √s(NN) = 2.76 TeV

The ALICE experiment has measured the inclusive J/ψ production in Pb-Pb collisions at √s(NN) = 2.76 TeV down to zero transverse momentum in the rapidity range 2.5 < y < 4. A suppression of the inclusive J/ψ yield in Pb-Pb is observed with respect to the one measured in pp collisions scaled by the number of binary nucleon-nucleon collisions. The nuclear modification factor, integrated over the 0%-80% most central collisions, is 0.545 ± 0.032(stat) ± 0.083(syst) and does not exhibit a significant dependence on the collision centrality. These features appear significantly different from measurements at lower collision energies. Models including J/ψ production from charm quarks in a deconfined partonic phase can describe our data.

Innovative magnetic scaffolds for orthopedic tissue engineering

The use of magnetism in tissue engineering is a very promising approach, in fact magnetic scaffolds are able not only to support tissue regeneration, but they can be activated and work like a magnet attracting functionalized magnetic nanoparticles (MNPs) injected close to the scaffold enhancing tissue regeneration. This study aimed to assess the in vivo biocompatibility and osteointegrative properties of novel magnetic scaffolds. Two hydroxyapatite/collagen (70/30 wt %) magnetic scaffolds were magnetized with two different techniques: direct nucleation of biomimetic phase and superparamagnetic nanoparticles (MNPs) on self-assembling collagen fibers (MAG-A) and scaffold impregnation in ferro-fluid solution (MAG-B). Magnetic scaffolds were implanted in rabbit distal femoral epiphysis and tibial mid-diaphysis. Histopathological screening showed no inflammatory reaction due to MNPs. Significantly higher bone healing rate (ΔBHR) results were observed in MAG-A in comparison to MAG-B. Significant differences were also found between experimental times with an increase in ΔBHR from 2 to 4 weeks for both scaffolds in trabecular bone, while only for MAG-B (23%, p < 0.05) in cortical bone. The proposed magnetic scaffolds seem to be promising for magnetic guiding in orthopedic tissue engineering applications and they will be suitable to treat also several pathologies in regenerative medicine area.

Particle-yield modification in jetlike azimuthal dihadron correlations in Pb-Pb collisions at √s(NN)=2.76 TeV

The yield of charged particles associated with high-p(t) trigger particles (8<p(t)<15 GeV/c) is measured with the ALICE detector in Pb-Pb collisions at √s(NN)=2.76 TeV relative to proton-proton collisions at the same energy. The conditional per-trigger yields are extracted from the narrow jetlike correlation peaks in azimuthal dihadron correlations. In the 5% most central collisions, we observe that the yield of associated charged particles with transverse momenta p(t)>3 GeV/c on the away side drops to about 60% of that observed in pp collisions, while on the near side a moderate enhancement of 20%-30% is found.

J/ψ polarization in pp collisions at √s=7 TeV

The ALICE Collaboration has studied J/ψ production in pp collisions at √s=7 TeV at the LHC through its muon pair decay. The polar and azimuthal angle distributions of the decay muons were measured, and results on the J/ψ polarization parameters λ(θ) and λ(φ) were obtained. The study was performed in the kinematic region 2.5<y<4, 2<p(t)<8 GeV/c, in the helicity and Collins-Soper reference frames. In both frames, the polarization parameters are compatible with zero, within uncertainties.

Higher harmonic anisotropic flow measurements of charged particles in Pb-Pb collisions at sqrt(s(NN)) = 2.76 TeV

We report on the first measurement of the triangular v3, quadrangular v4, and pentagonal v5 charged particle flow in Pb-Pb collisions at sqrt(s(NN)) = 2.76  TeV measured with the ALICE detector at the CERN Large Hadron Collider. We show that the triangular flow can be described in terms of the initial spatial anisotropy and its fluctuations, which provides strong constraints on its origin. In the most central events, where the elliptic flow v2 and v3 have similar magnitude, a double peaked structure in the two-particle azimuthal correlations is observed, which is often interpreted as a Mach cone response to fast partons. We show that this structure can be naturally explained from the measured anisotropic flow Fourier coefficients.

A microflow cytometer exploited for the immunological differentiation of leukocytes

In this article, we demonstrate the potential of a microfluidic chip for the differentiation of immunologically stained blood cells. To this end, white blood cells stained with antibodies typically applied for the determination of the immune status were measured in the micro-device. Relative concentrations of lymphocytes and subpopulations of lymphocytes are compared to those obtained with a conventional flow cytometer. The stability of the hydrodynamic focusing and the optical setup was determined by measuring the variation of the signal pulse height of fluorescence calibration beads, being about 2% for the micro-device. This value and the overall performance of the micro-device are similar to conventional flow cytometers. It follows from our results that such microfluidic structures are well suited as modules in a compact, portable read-out instrument. The production process of the microflow cytometers, which we exploited for immunological cell differentiation, is compatible with mass production technology like injection molding and, hence, low cost disposable chips could be available in the future.

Centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV

The centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at sqrt[s_{NN}]=2.76  TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of 2 from peripheral (70%-80%) to central (0%-5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.

Elliptic flow of charged particles in Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at sqrt[S(NN)] =2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η|<0.8) and transverse momentum range 0.2<p t<5.0 GeV/c. The elliptic flow signal v₂, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 ± 0.002(stat) ± 0.003(syst) in the 40%-50% centrality class. The differential elliptic flow v₂ p t reaches a maximum of 0.2 near p t =3 GeV/c. Compared to RHIC Au-Au collisions at sqrt[S(NN)] 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.

Charged-particle multiplicity density at midrapidity in central Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

The first measurement of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at a center-of-mass energy per nucleon pair √ S NN = 2.76 TeV is presented. For an event sample corresponding to the most central 5% of the hadronic cross section, the pseudorapidity density of primary charged particles at midrapidity is 1584 ± 4(stat) ± 76(syst), which corresponds to 8.3 ± 0.4(syst) per participating nucleon pair. This represents an increase of about a factor 1.9 relative to pp collisions at similar collision energies, and about a factor 2.2 to central Au-Au collisions at √ S NN = 2.76 TeV. This measurement provides the first experimental constraint for models of nucleus-nucleus collisions at LHC energies.

Midrapidity antiproton-to-proton ratio in pp collisons at sqrt[s]=0.9 and 7 TeV measured by the ALICE experiment

The ratio of the yields of antiprotons to protons in pp collisions has been measured by the ALICE experiment at sqrt[s]=0.9 and 7 TeV during the initial running periods of the Large Hadron Collider. The measurement covers the transverse momentum interval 0.45<p_{t}<1.05  GeV/c and rapidity |y|<0.5. The ratio is measured to be R_{|y|<0.5}=0.957±0.006(stat)±0.014(syst) at 0.9 TeV and R_{|y|<0.5}=0.991±0.005(stat)±0.014(syst) at 7 TeV and it is independent of both rapidity and transverse momentum. The results are consistent with the conventional model of baryon-number transport and set stringent limits on any additional contributions to baryon-number transfer over very large rapidity intervals in pp collisions.

Statistical mechanics model for the transit free energy of monatomic liquids

In applying vibration-transit (V-T) theory of liquid dynamics to the thermodynamic properties of monatomic liquids, the point has been reached where an improved model is needed for the small (approximately 10%) transit contribution. Toward this goal, an analysis of the available high-temperature experimental entropy data for elemental liquids was recently completed [D. C. Wallace, E. D. Chisolm, and N. Bock, Phys. Rev. E 79, 051201 (2009)]. This analysis yields a common curve of transit entropy vs T/thetatr, where T is temperature and thetatr is a scaling temperature for each element. In the present paper, a statistical mechanics model is constructed for the transit partition function, and is calibrated to the experimental transit entropy curve. The model has two scalar parameters, and captures the temperature scaling of experiment. The calibrated model fits the experimental liquid entropy to high accuracy at all temperatures. With no additional parameters, the model also agrees with both experiment and molecular dynamics for the internal energy vs. T for Na. With the calibrated transit model, V-T theory provides equations subject to ab initio evaluation for thermodynamic properties of monatomic liquids. This will allow the range of applicability of the theory, and its overall accuracy, to be determined. More generally, the hypothesis of V-T theory, which divides the many-atom potential energy valleys into random and symmetric classes, can also be tested for its application beyond monatomic systems.

Methylphenidate normalizes elevated dopamine transporter densities in an animal model of the attention-deficit/hyperactivity disorder combined type, but not to the same extent in one of the attention-deficit/hyperactivity disorder inattentive type

The spontaneously hypertensive rat (SHR/NCrl) is a validated model of attention-deficit/hyperactivity disorder (ADHD) combined subtype, whereas a recently identified substrain of the Wistar Kyoto rat (WKY/NCrl) is a model of ADHD inattentive subtype. In this study, we first examined the expression of genes involved in dopamine signaling and metabolism in the dorsal striatum and ventral mesencephalon of these two rat strains, as well as three reference control strains (WKY/NHsd, WK/HanTac, and SD/NTac) using quantitative real time RT-PCR. Next, striatal dopamine transporter (DAT) density was determined by ligand binding assay in the two ADHD-like strains at different developmental stages and after methylphenidate treatment. In adult rats, the mRNA expression of DAT and tyrosine hydroxylase was elevated in SHR/NCrl and WKY/NCrl rats compared to control strains, with differences between SHR/NCrl and WKY/NCrl rats also evident. During normal development, changes of striatal DAT densities occurred in both strains with lower densities in WKY/NCrl compared to SHR/NCrl after day 25. Two-weeks methylphenidate treatment during different developmental stages was associated with decreased striatal DAT density in both rat strains compared to the non-treated rats with more pronounced effects followed prepubertal treatment. These results suggest differences in the pathophysiology of the combined versus the predominantly inattentive animal model of ADHD. Finally, treatment with methylphenidate might reduce elevated DAT levels more effectively in the combined subtype especially when applied before puberty.

A novel route in bone tissue engineering: magnetic biomimetic scaffolds

In recent years, interest in tissue engineering and its solutions has increased considerably. In particular, scaffolds have become fundamental tools in bone graft substitution and are used in combination with a variety of bio-agents. However, a long-standing problem in the use of these conventional scaffolds lies in the impossibility of re-loading the scaffold with the bio-agents after implantation. This work introduces the magnetic scaffold as a conceptually new solution. The magnetic scaffold is able, via magnetic driving, to attract and take up in vivo growth factors, stem cells or other bio-agents bound to magnetic particles. The authors succeeded in developing a simple and inexpensive technique able to transform standard commercial scaffolds made of hydroxyapatite and collagen in magnetic scaffolds. This innovative process involves dip-coating of the scaffolds in aqueous ferrofluids containing iron oxide nanoparticles coated with various biopolymers. After dip-coating, the nanoparticles are integrated into the structure of the scaffolds, providing the latter with magnetization values as high as 15 emu g(-)(1) at 10 kOe. These values are suitable for generating magnetic gradients, enabling magnetic guiding in the vicinity and inside the scaffold. The magnetic scaffolds do not suffer from any structural damage during the process, maintaining their specific porosity and shape. Moreover, they do not release magnetic particles under a constant flow of simulated body fluids over a period of 8 days. Finally, preliminary studies indicate the ability of the magnetic scaffolds to support adhesion and proliferation of human bone marrow stem cells in vitro. Hence, this new type of scaffold is a valuable candidate for tissue engineering applications, featuring a novel magnetic guiding option.

Ab initio method for locating characteristic potential-energy minima of liquids

It is possible in principle to probe the many-atom potential surface using density functional theory (DFT). This will allow us to apply DFT to the Hamiltonian formulation of atomic motion in monatomic liquids by Wallace [Phys. Rev. E 56, 4179 (1997)]. For a monatomic system, analysis of the potential surface is facilitated by the random and symmetric classification of potential-energy valleys. Since the random valleys are numerically dominant and uniform in their macroscopic potential properties, only a few quenches are necessary to establish these properties. Here we describe an efficient technique for doing this. Quenches are done from easily generated "stochastic" configurations, in which the nuclei are distributed uniformly within a constraint limiting the closeness of approach. For metallic Na with atomic pair potential interactions, it is shown that quenches from stochastic configurations and quenches from equilibrium liquid molecular dynamics configurations produce statistically identical distributions of the structural potential energy. Again for metallic Na, it is shown that DFT quenches from stochastic configurations provide the parameters which calibrate the Hamiltonian. A statistical mechanical analysis shows how the underlying potential properties can be extracted from the distributions found in quenches from stochastic configurations.

Bruchpilot in ribbon-like axonal agglomerates, behavioral defects, and early death in SRPK79D kinase mutants of Drosophila

Defining the molecular structure and function of synapses is a central theme in brain research. In Drosophila the Bruchpilot (BRP) protein is associated with T-shaped ribbons ("T-bars") at presynaptic active zones (AZs). BRP is required for intact AZ structure and normal evoked neurotransmitter release. By screening for mutations that affect the tissue distribution of Bruchpilot, we have identified a P-transposon insertion in gene CG11489 (location 79D) which shows high homology to mammalian genes for SR protein kinases (SRPKs). SRPKs phosphorylate serine-arginine rich splicing factors (SR proteins). Since proteins expressed from CG11489 cDNAs phosphorylate a peptide from a human SR protein in vitro, we name CG11489 the Drosophila Srpk79D gene. We have characterized Srpk79D transcripts and generated a null mutant. Mutation of the Srpk79D gene causes conspicuous accumulations of BRP in larval and adult nerves. At the ultrastructural level, these correspond to extensive axonal agglomerates of electron-dense ribbons surrounded by clear vesicles. Basic synaptic structure and function at larval neuromuscular junctions appears normal, whereas life expectancy and locomotor behavior of adult mutants are significantly impaired. All phenotypes of the mutant can be largely or completely rescued by panneural expression of SRPK79D isoforms. Isoform-specific antibodies recognize panneurally overexpressed GFP-tagged SRPK79D-PC isoform co-localized with BRP at presynaptic active zones while the tagged -PB isoform is found in spots within neuronal perikarya. SRPK79D concentrations in wild type apparently are too low to be revealed by these antisera. We propose that the Drosophila Srpk79D gene characterized here may be expressed at low levels throughout the nervous system to prevent the assembly of BRP containing agglomerates in axons and maintain intact brain function. The discovery of an SR protein kinase required for normal BRP distribution calls for the identification of its substrate and the detailed analysis of SRPK function for the maintenance of nervous system integrity.

Tuberculosis case finding and preventive therapy in an HIV voluntary counseling and testing center in Uganda

SETTING

A large, urban human immunodeficiency virus (HIV) voluntary counseling and testing (VCT) center in Kampala, Uganda.

OBJECTIVE

Tuberculosis (TB) is a leading cause of morbidity and mortality in persons with HIV infection in sub-Saharan Africa. Intensified TB case finding and use of isoniazid preventive therapy (IPT) for latent infection reduces the burden of TB, but few programs have been implemented due to concerns about feasibility.

DESIGN

Retrospective evaluation of a TB case finding and IPT program.

RESULTS

Over a 25-month period, 6305 patients newly diagnosed with HIV infection underwent evaluation: 293 (5%) had TB disease; 1955 (37%) patients were not eligible for preventive therapy because they lived > 20 km away, had advanced HIV disease, or had previously had TB. Of 3366 who had a tuberculin skin test (TST) placed, 2548 (76%) had the TST read; 894 (35%) of these were positive. Of 506 persons who started treatment, 335 (66%) completed it.

CONCLUSION

This unique program was feasible, detected a high proportion of undiagnosed TB, and successfully treated persons with latent infection. Expanding access to HIV VCT as well as collaboration between HIV/ AIDS and TB programs can increase the proportion of HIV-infected persons who can benefit from these programs.