Pseudorapidity density of charged particles in p+Pb collisions at √(s(NN))=5.02 TeV

The charged-particle pseudorapidity density measured over four units of pseudorapidity in nonsingle-diffractive p+Pb collisions at a center-of-mass energy per nucleon pair √(s(NN))=5.02 TeV is presented. The average value at midrapidity is measured to be 16.81±0.71 (syst), which corresponds to 2.14±0.17 (syst) per participating nucleon, calculated with the Glauber model. This is 16% lower than in nonsingle-diffractive pp collisions interpolated to the same collision energy and 84% higher than in d+Au collisions at s√(s(NN))=0.2 TeV. The measured pseudorapidity density in p+Pb collisions is compared to model predictions and provides new constraints on the description of particle production in high-energy nuclear collisions.

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.

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.

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.

Conditional knockout of Lgr4 leads to impaired ductal elongation and branching morphogenesis in mouse mammary glands

We have analyzed the function of LGR4 in the development of various mouse epithelial tissues. Here we first report the retarded invasion of mammary ducts into the fat pad observed in Lgr4(K5 KO) mice at 4 weeks, compared with that of age-matched Lgr4(K5 ctrl). Furthermore, we demonstrate a significant decrease in mammary ductal branching in Lgr4(K5 KO) at several stages (4, 6 and 8 weeks). On the other hand, immunohistochemical analysis of the mammary gland of Lgr4(K5 KO) using anti-αSMA, anti-K18 and anti-laminin antibodies showed structures similar to those of Lgr4(K5 ctrl) mammary glands. In addition, we did not detect significant differences in the expression of ERα, which was suggested to be a downstream molecule of LGR4, and Lgr4(K5 KO) showed no retarded invasion in the response to 17β-estradiol administration. Furthermore, the phosphorylated form of Smad1/5/8 was normally detected in the mammary gland of Lgr4(K5 KO).

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.

[Video-assisted thoracic surgery for pneumothorax in patients over fifty years of age]

BACKGROUND

Pneumothorax in middle-aged and elderly patients has various different features from young patients. We set out to investigate the outcome and usefulness of video-assisted thoracic surgery (VATS) in this group.

PATIENTS AND METHODS

From January 1993 to August 2010, 168 patients underwent a total of 178 thoracoscopic surgeries. There were 160 men and 8 women with mean age of 67 (range, 50 to 85). The average duration of thoracic drainage before surgery was 7.4 days. We excised only responsible lesions as minimum degree of dissection as possible. When patients have intractable air leakage and chest computed tomography (CT) indicates severe pleural adhesions, pleurography should be performed to locate the site of air leakage and determine surgical approaches. One hundred and seventy patients were treated with the lateral approach, while 8 patients were successfully treated with the anterior approach. One hundred and fifty-one patients were treated with VATS alone, and 27 patients were treated with the combination of VATS and small thoracotomy. The duration of chest tube drainage, hospital stay, post-operative complication, outcome and recurrence were assessed.

RESULTS

The air leakages stopped and all patients except for 2 patents were discharged without drainage tubes. Postoperative drainage time was 4.5 +/- 3.4 days. Postoperative hospital stay was 9.9 +/- 13.9 days. One patient died caused by perioperative myocardial infarction. Seventeen patients died of other diseases. Seven patients needed local hospital treatments and the recurrence rate was 3.9%.

CONCLUSION

VATS for pneumothorax in patients over 50 years old is very useful by appropriate perioperative managements.

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.

Learning of thoracoscopic radical esophagectomy: how can the learning curve be made short and flat?

Attainment of proficiency in video-assisted thoracoscopic radical esophagectomy (VATS) for thoracic esophageal cancer requires much experience. We have mastered this procedure safely under the direction of an experienced surgeon. After adoption of the procedure, the educated surgeon directed induction of this surgical procedure at another institution. We evaluated the efficacy of instruction during the induction period by comparing the results at the two institutions in which VATS had been newly induced. We defined the induction period as the time from the beginning of VATS to the time when the last instruction was carried out. From January 2003 to December 2007, 53 patients were candidates for VATS at Kanazawa University (institution 1). Of these, 46 patients underwent curative VATS by a single operator. We divided this period into three parts: the induction period of VATS, post-induction period, and proficient period when the educated surgeon of institution 1 directed the procedure at Maebashi Red Cross Hospital (institution 2). At institution 1, 12 VATS were scheduled, and nine procedures (75%) (group A) including eight instructions were completed during the induction period (from January 2003 to August 2004). Thereafter, VATS was performed without instruction. In the post-induction period, nine VATS were scheduled, and eight procedures (88.8%) (group B) were completed from September 2004 to August 2005. Subsequently, 32 VATS were scheduled, and 29 procedures (90.6%) (group C) were completed during the proficient period (from September 2005 to December 2007). The surgeon at Maebashi Red Cross Hospital (institution 2) started to perform VATS under the direction of the surgeon who had been educated at institution 1 from September 2005. VATS was completed in 13 (76.4%) (group D) of 17 cases by a single surgeon including seven instructions during the induction period at institution 2 from September 2005 to December 2007. No lethal complication occurred during the induction period at both institutions. We compared the results of VATS among four groups from the two institutions. There were no differences in the background and clinicopathological features among the four groups. The number of dissected lymph nodes and amount of thoracic blood loss were similar in the four groups (35 [22-52] vs 41 [26-53] vs 32 [17-69] vs 29 [17-42] nodes, P = 0.139, and 170 [90-380] vs 275 [130-550] vs 220 [10-660] vs 210 [75-543] g, P = 0.373, respectively). There was no difference in the duration of the thoracic procedure during the induction period at the two institutions. However, the duration of the procedure was significantly shorter in the proficient period of institution 1 (group C: 266 [195-555] minutes) than in the induction period of both institutions (group A: 350 [280-448] minutes [P = 0.005] and group D: 345 [270-420] mL [P = 0.002]). There were no surgery-related deaths in any of the groups. The incidence of postoperative complications did not differ among the four groups. Thoracoscopic radical esophagectomy can be mastered quickly and safely with a flat learning curve under the direction of an experienced surgeon. The educated surgeon can instruct surgeons at another institution on how to perform thoracoscopic esophagectomy. The operation time of thoracoscopic surgery is shortened by experience.

Heritabilities and genetic correlations of fatty acid compositions in longissimus muscle lipid with carcass traits in Japanese Black cattle

Fatty acid composition and carcass traits of 2,275 Japanese Black steers and heifers were analyzed to estimate the heritabilities and genetic correlations using the REML procedure. Slices of LM at the 6th to 7th rib section were minced and homogenized, and total lipids were extracted for the analysis by a gas chromatograph. Oleic acid accounted for the majority (51.3%), followed by palmitic (26.4%) and stearic (10.8%) acids. Heritabilities of carcass traits were moderate to high, ranging from 0.34 to 0.61, and heritabilities of individual fatty acids varied largely from 0.00 to 0.78. Those of MUFA, SFA, and PUFA were estimated to be 0.68, 0.66, and 0.47, respectively. Predicted breeding values for MUFA in 99 sires ranged from -3.0 to 5.4%. Genetic correlations of fatty acid compositions with carcass traits were generally weak (-0.28 to 0.39). Low but positive genetic correlations were obtained between beef marbling, on which emphasis of selection has been placed, and oleic acid (0.19) or MUFA (0.23). The results indicated the possibility not only for genetic improvement in fat quality traits but also simultaneous improvements with carcass traits by appropriate selection program.

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.

Prospective randomized controlled study on the effects of perioperative administration of a neutrophil elastase inhibitor to patients undergoing video-assisted thoracoscopic surgery for thoracic esophageal cancer

Sivelestat sodium hydrate (Ono Pharmaceutical Co., Osaka, Japan) is a selective inhibitor of neutrophil elastase (NE) and is effective in reducing acute lung injury associated with systemic inflammatory response syndrome (SIRS). We conducted a prospective randomized controlled study to investigate the efficacy of perioperative administration of sivelestat sodium hydrate to prevent postoperative acute lung injury in patients undergoing thoracoscopic esophagectomy and radical lymphadenectomy. Twenty-two patients with thoracic esophageal cancer underwent video-assisted thoracoscopic esophagectomy with extended lymph node dissection in our institution between April 2007 and November 2008. Using a double-blinded method, these patients were randomly assigned to one of two groups preoperatively. The active treatment group received sivelestat sodium hydrate intravenously for 72 hours starting at the beginning of surgery (sivelestat-treated group; n= 11), while the other group received saline (control group; n= 11). All patients were given methylprednisolone immediately before surgery. Postoperative clinical course was compared between the two groups. Two patients (one in each group) were discontinued from the study during the postoperative period because of surgery-related complications. Of the remaining 20 patients, 2 patients who developed pneumonia within a week after surgery were excluded from some laboratory analyses, so data from 18 patients (9 patients in each group) were analyzed based on the arterial oxygen pressure/fraction of inspired oxygen ratio, white blood cell count, serum C-reactive protein level, plasma cytokine levels, plasma NE level, and markers of alveolar type II epithelial cells. In the current study, the incidence of postoperative morbidity did not differ between the two groups. The median duration of SIRS in the sivelestat-treated group was significantly shorter than that in the control group: 17 (range 9-36) hours versus 49 (15-60) hours, respectively (P= 0.009). Concerning the parameters used for the diagnosis of SIRS, the median heart rates on postoperative day (POD) 2 were significantly lower in the sivelestat-treated group than in the control group (P= 0.007). The median arterial oxygen pressure/fraction of inspired oxygen ratio of the sivelestat-treated group were significantly higher than those of the control group on POD 1 and POD 7 (POD 1: 372.0 [range 284.0-475.0] vs 322.5 [243.5-380.0], respectively, P= 0.040; POD 7: 377.2 [339.5-430.0] vs 357.6 [240.0-392.8], P= 0.031). Postoperative white blood cell counts, serum C-reactive protein levels, plasma interleukin-1beta, tumor necrosis factor-alpha levels, and plasma NE levels did not differ significantly between the two groups at any point during the postoperative course, nor did serum Krebs von den Lungen 6, surfactant protein-A, or surfactant protein-D levels, which were used as markers of alveolar type II epithelial cells to evaluate the severity of lung injury. Plasma interleukin-8 levels were significantly lower in the sivelestat-treated group than in the control group on POD 3 (P= 0.040). In conclusion, perioperative administration of sivelestat sodium hydrate (starting at the beginning of surgery) mitigated postoperative hypoxia, partially suppressed postoperative hypercytokinemia, shortened the duration of SIRS, and stabilized postoperative circulatory status after thoracoscopic esophagectomy.

Prevention of neural tube defects by loss of function of inducible nitric oxide synthase in fetuses of a mouse model of streptozotocin-induced diabetes

AIMS/HYPOTHESIS

Maternal diabetes during pregnancy increases the risk of congenital malformations such as neural tube defects (NTDs). Although the mechanism of this effect is uncertain, it is known that levels of nitric oxide synthase (NOS) and nitric oxide are elevated in embryos of a mouse model of diabetes. We postulated that overproduction of nitric oxide causes diabetes-induced congenital malformations and that inhibition of inducible NOS (iNOS) might prevent diabetic embryopathy.

METHODS

Mice were rendered hyperglycaemic by intraperitoneal injection of streptozotocin. The incidence of congenital malformations including NTDs was evaluated on gestational day 18.5. We assessed the involvement of iNOS in diabetes-induced malformation by administering ONO-1714, a specific inhibitor of iNOS, to pregnant mice with streptozotocin-induced diabetic mice and by screening mice with iNOS deficiency due to genetic knockout (iNos(-/-)).

RESULTS

ONO-1714 markedly reduced the incidence of congenital anomalies, including NTDs, in fetuses of a mouse model of diabetes. It also prevented apoptosis in the head region of fetuses, indicating that iNOS is involved in diabetes-related congenital malformations. Indeed, no NTDs were observed in fetuses of diabetic iNos(-/-) mice and the incidence of other malformations was also markedly reduced.

CONCLUSIONS/INTERPRETATION

We conclude that increased iNOS activity during organogenesis plays a crucial role in the pathogenesis of diabetes-induced malformations and suggest that inhibitors of iNOS might help prevent malformations, especially NTDs, in diabetic pregnancy.

Alpha-lipoic acid reduces congenital malformations in the offspring of diabetic mice

BACKGROUND

The mechanism of diabetes-induced congenital malformation remains to be elucidated. It has been reported that alpha-lipoic acid (LA) prevents neural tube defects (NTDs) in offsprings of rats with streptozotocin-induced diabetes. Here, we evaluate the protective effect of LA against diabetic embryopathy, including NTDs, cardiovascular malformations (CVMs), and skeletal malformations, in mice.

METHODS

Female mice were rendered hyperglycemic using streptozotocin and then mated with normal male mouse. Pregnant diabetic or non-diabetic mice were treated daily with either LA (100 mg/kg body weight) or saline between gestational days 0 and 18. On day 18, fetuses were examined for congenital malformations.

RESULTS

Plasma glucose levels on day 18 were not affected by LA treatment. No congenital malformations were observed either in the saline-treated or LA-treated non-diabetic group. In the saline-treated diabetic group, 39% of fetuses had external malformations and 30% had NTDs. In the LA-treated diabetic group, the corresponding proportions were 11 and 8%, respectively. LA treatment also decreased the incidence of CVMs from 30-3% and of skeletal malformations from 29-6%.

CONCLUSIONS

We conclude that LA can reduce NTDs, CVMs and skeletal malformations in the offspring of diabetic mice at term delivery.

Lateral supraorbital keyhole approach to clip unruptured anterior communicating artery aneurysms

OBJECT

Clipping of an anterior communicating artery (A-com A) aneurysm requires various working angles for safe manipulation and observation. The lateral supraorbital keyhole approach provides a more lateral subfrontal corridor to observe and clip an A-com A aneurysm than the standard Perneczky method.

METHODS

Preoperative planning was individualized in each patient based on three-dimensional computed tomography (3D-CT) angiography and 3D-CT osteotomy planning images. The procedure consisted of a 40-50 mm periorbital skin incision, partial dissection of the anterior portion of the temporal muscle, a 35 x 25 mm keyhole minicraniotomy from the supraorbital area to the sphenoid ridge, and opening of the carotid cistern and sylvian fissure in an antegrade fashion. Ten keyhole clipping procedures were performed in 10 patients with unruptured A-com A aneurysms.

RESULTS

No shaving of scalp hair, drain placement, or anticonvulsant medication were required. No patient suffered neurological deficits or abnormal findings on postoperative magnetic resonance imaging. Most patients were discharged on the 2nd to 3rd postoperative days except for one patient who suffered from meningitis.

CONCLUSIONS

The lateral supraorbital keyhole approach is a minimally invasive treatment option for relatively small and unruptured A-com A aneurysms.