Diastereo- and Enantioselective Synthesis of Tetracyclic Cycloheptanols through (4+3) Annulation via C-C/C-H Activation Cascade

Transition metal-catalyzed annulations of four-membered rings via C-C activation are powerful tools to construct complex fused and bridged ring systems. Despite significant progress in (4+1), (4+2) and (4+4) annulations, the (4+3) annulation remains unexplored. Herein, we develop an asymmetric Rh-catalyzed intramolecular (4+3) annulation of α-arylalkene-tethered benzocyclobutenols for the synthesis of dihydrofuran-annulated dibenzocycloheptanols with two discontinuous chiral carbon centers via a C-C and C-H activation cascade. The reaction features excellent diastereo- and enantioselectivities and 100 % atom economy, and is applicable to late-stage modification of complex molecules.

[Establishment method and significance of birthweight curve and reference in single center]

Objective: To establish neonatal birthweight percentile curves based on single-center cohort database using different methods, compare them with the current national birthweight curves and discuss the appropriateness and significance of single-center birthweight standard. Methods: Based on a prospective first-trimester screening cohort at Nanjing Drum Tower Hospital from January 2017 to February 2022, the generalized additive models for location, scale and shape (GAMLSS) and semi-customized method were applied to generate local birthweight percentile curves (hereinafter referred to as the local GAMLSS curves, semi-customized curves) for 3 894 cases who were at low risk of small for gestation age (SGA) and large for gestation age (LGA). Infants were categorized as SGA (birth weight<10th centile) by both semi-customized and local GAMLSS curves, semi-customized curves only, or not SGA (met neither criteria). The incidence of adverse perinatal outcome between different groups was compared. The same method was used to compare the semi-customized curves with the Chinese national birthweight curves (established by GAMLSS method as well, hereinafter referred to as the national GAMLSS curves). Results: (1) Among the 7 044 live births, 404 (5.74%, 404/7 044), 774 (10.99%, 774/7 044) and 868 (12.32%, 868/7 044) cases were diagnosed as SGA according to the national GAMLSS curves, the local GAMLSS curves and the semi-customized curves respectively. The birth weight of the 10th percentile of the semi-customized curves was higher than that of the local GAMLSS curves and the national GAMLSS curves at all gestational age. (2) When comparing semi-customized curves and the local GAMLSS curves, the incidence of admission to neonatal intensive care unit (NICU) for more than 24 hours of infants identified as SGA by semi-customized curves only (94 cases) and both semi-customized and local GAMLSS curves (774 cases) was 10.64% (10/94) and 5.68% (44/774) respectively, both significantly higher than that in non SGA group [6 176 cases, 1.34% (83/6 176); P<0.001]. The incidence of preeclampsia, pregnancy<34 weeks, and pregnancy<37 weeks of infants identified as SGA by the semi-customized curves only and both semi-customized and local GAMLSS curves was 12.77% (12/94) and 9.43% (73/774), 9.57% (9/94) and 2.71% (21/774), 24.47% (23/94) and 7.24% (56/774) respectively, which were significantly higher than those of the non SGA group [4.37% (270/6 176), 0.83% (51/6 176), 4.23% (261/6 176); all P<0.001]. (3) When comparing semi-customized curves and the national GAMLSS curves, the incidence of admission to NICU for more than 24 hours of infants identified as SGA by semi-customized curves only (464 cases) and both semi-customized and national GAMLSS curves (404 cases) was 5.60% (26/464) and 6.93% (28/404) respectively, both significantly higher than that in non SGA group [6 176 cases, 1.34% (83/6 176); all P<0.001]. The incidence of emergency cesarean section or forceps delivery for non-reassuring fetal status (NRFS) in infants identified as SGA by semi-customized curves only and both semi-customized and national GAMLSS curves was 4.96% (23/464) and 12.38% (50/404), both significantly higher than that in the non SGA group [2.57% (159/6 176); all P<0.001]. The incidence of preeclampsia, pregnancy<34 weeks, and pregnancy<37 weeks in the semi-customized curves only group and both semi-customized and national GAMLSS curves group was 8.84% (41/464) and 10.89% (44/404), 4.31% (20/464) and 2.48% (10/404), 10.56% (49/464) and 7.43% (30/404) respectively, all significantly higher than those in the non SGA group [4.37% (270/6 176), 0.83% (51/6 176), 4.23% (261/6 176); all P<0.001]. Conclusion: Compared with the national GAMLSS birthweight curves and the local GAMLSS curves, the birth weight curves established by semi-customized method based on our single center database is in line with our center' SGA screening, which is helpful to identify and strengthen the management of high-risk infants.

[Clinical analysis of 7 cases of pregnancy with non-Hodgkin lymphoma]

Objective: To investigate the clinicopathological features, diagnosis, treatment and outcomes of pregnancy with non-Hodgkin lymphoma (NHL). Methods: The clinicopathological data of 7 patients of pregnancy with NHL admitted to Nanjing Drum Tower Hospital from January 2010 to May 2022 were reviewed. General information, diagnosis, treatment and maternal and child outcomes were retrospectively analyzed. Results: (1) The median age of the 7 patients was 28 years old (range: 26-33 years); 3 cases complained of abdominal pain (2 cases of huge pelvic or abdominal mass with multiple metastases), 2 cases of cough (1 case with superior vena cava syndrome), 1 case of facial swelling and pain, and 1 case of poor appetite. The median time from the onset of symptoms to initial visit was 30 days (range: 15-188 days). (2) Only 3 cases were diagnosed during pregnancy through biopsy, and the biopsy sites including right nasal vestibular mass, left supraclavicular lymph node and lung respectively. One case was suspected to be splenic marginal zone lymphoma through bone marrow puncture during pregnancy, and confirmed by pathological results observed in splenectomy specimens after termination of pregnancy. Three cases were diagnosed as NHL by pathological results of focus biopsy or partial tumor resection during cesarean section. Pathological types: 5 cases of diffuse large B cell lymphoma, one splenic marginal zone lymphoma and one nasal cavity natural killer (NK)/T cell lymphoma. Stages: 1 case of stage Ⅱ, 6 cases of stage Ⅳ. Pathological examination of placentas was performed for 4 patients after delivery, included one case with tumor metastasis to the placenta. (3) Among the 7 patients, 1 case was induced in the second trimester; 5 cases were terminated by cesarean section in the third trimester, all of which were premature; one case of full-term was delivered with forceps. All 6 neonates survived healthy. Treatments: 5 cases received chemotherapy after termination of pregnancy (included 1 case received autologous hematopoietic stem cell retransfusion therapy after chemotherapy), and 1 case received chemotherapy combined nasopharyngeal radiotherapy, and six cases survived without recurrence (follow-up until October 2022). The other case was a patient with hepatitis B virus infection and congenital heart disease who died of multiple organ failure 18 days after cesarean section. Conclusions: It is difficult to diagnose, necessary to pay attention to the complaints of pregnant women, and to actively carry out related examinations during pregnancy. When the lesion involves multiple organs, the possibility of lymphoma should be considered. Pregnancy with NHL is sensitive to chemotherapy. Even for advanced patients, good outcome could still be obtained after standardized treatment.

[Risk factors and characteristics of gut microbiota and metabolites in inflammatory bowel diseases patients with urolithiasis]

Objective: To identify the related factors and characteristics of gut microbiota and metabolites in inflammatory bowel disease (IBD) patients with urolithiasis. Methods: A total of 68 IBD patients with urolithiasis and 136 gender-and age-matched IBD patients without urolithiasis in the Department of Gastroenterology, Peking Union Medical College Hospital from January 2014 to December 2019 were recruited. The diagnosis of urolithiasis was confirmed by plain films, ultrasonography, abdominal computed tomography or intravenous urography. The clinical data of patients were collected, and the association between the clinical characteristics and urolithiasis was further analyzed. The fecal samples were collected from 10 patients with urolithiasis and 18 patients without urolithiasis, and the gut microbiota and metabolites composition were analyzed. Results: There were 49 male and 19 female IBD patients with urolithiasis, with a mean age of (36.0±12.4) years, and 98 male and 38 female patients without urolithiasis, with a mean age of (36.1±12.5) years. Univariate analysis revealed that the rate of ileostomy and the resection of small intestine in Crohn's disease (CD) patients with urolithiasis (n=34) was significantly higher than CD patients without urolithiasis (n=68) (26.5% vs 7.4%, P=0.019). And the erythrocyte sedimentation rate was also higher [26.5 (12.0, 40.8) vs 13.0 (7.2, 32.5) mm/1 h, P=0.022] in CD patients with urolithiasis. There were no significant differences in clinical characteristics and biochemical parameters between the ulcerative colitis (UC) patients with urolithiasis (n=34) and without urolithiasis (n=68) (all P>0.05). The multivariate logistic regression analysis indicated that ileostomy and the resection of small intestine were the independent related factors for urolithiasis in CD patients (OR=4.619, 95%CI: 1.178-18.111, P=0.028). There was no significant difference in α and β diversity between the two groups (all P>0.05). At the phylum level, there was no significant difference in the abundance of microbiota (all P>0.05). At the genus level, the abundance of Enterococcus (P=0.049), Eubacterium_eligens (P=0.036) was significantly decreased. At the species level, the abundance of Bacteroides_coprocola was increased in urolithiasis group (P=0.035), while the abundance of Blautia_caecimuris was significantly decreased (P=0.042). No significant difference was found in fecal metabolites between the two groups (all P>0.05). According to LDA effect size (Lefse) analysis, taxa including Sphingomonadales, Fenollaria, Bacteroides_coprocola contributed greatly to the difference between the two groups. Conclusions: Ileostomy and the resection of small intestine are related factors for urolithiasis in patients with CD. Gut microbiota may be involved in the occurrence of urolithiasis in patients with IBD.

[Safety analysis of cesarean myomectomy in twin pregnancies with intramural myomas]

Objective: To estimate the safety of myomectomy in twin pregnant women with intramural myomas during cesarean section. Methods: The clinical data of 145 cases of twin pregnancies with intramural myomas who were delivered by cesarean section in Beijing Obstetrics and Gynecology Hospital, Capital Medical University from June 2013 to December 2021 were collected. Maternal demographics, fibroids' characteristics, maternal and fetal outcomes were compared between groups of cesarean section with myomectomy (myomectomy group, 49 cases) and cesarean section only (non-myomectomy group, 96 cases). Results: Compared with non-myomectomy group, myomectomy group had significantly prolonged operative time [50.0 minutes (37.5-57.5 minutes) vs 40.0 minutes (35.0-50.0 minutes), respectively; P=0.007] and significantly longer postoperative hospital stay [4.0 days (3.0-4.0 days) vs 3.0 days (3.0-4.0 days), respectively; P=0.047). Other maternal and fetal outcomes such as estimated blood loss, hemoglobin difference, postpartum hemorrhage, blood transfusion, B-Lynch structure, uterine artery ligation, postoperative fever and neonatal Apgar score showed no significant differences (all P>0.05). For intramural myomas <5 cm, there were no significant differences in maternal and fetal outcomes between myomectomy group and non-myomectomy group (all P>0.05). For intramural myomas ≥5 cm, operative time [55.0 minutes (40.0-60.0 minutes) vs 42.5 minutes (40.0-50.0 minutes), respectively; P=0.019] was significantly prolonged, postoperative hospital stay [4.0 days (4.0-5.0 days) vs 4.0 days (3.0-4.0 days), respectively; P=0.048] was significantly longer in myomectomy group than non-myomectomy group, but there were no significant differences in other maternal and fetal outcomes (all P>0.05). Conclusion: For twin pregnancies with intramural myomas, it is safe and feasible to remove intramural myomas during cesarean section by experienced obstetricians.

Photocurrent-driven transient symmetry breaking in the Weyl semimetal TaAs

Symmetry plays a central role in conventional and topological phases of matter, making the ability to optically drive symmetry changes a critical step in developing future technologies that rely on such control. Topological materials, like topological semimetals, are particularly sensitive to a breaking or restoring of time-reversal and crystalline symmetries, which affect both bulk and surface electronic states. While previous studies have focused on controlling symmetry via coupling to the crystal lattice, we demonstrate here an all-electronic mechanism based on photocurrent generation. Using second harmonic generation spectroscopy as a sensitive probe of symmetry changes, we observe an ultrafast breaking of time-reversal and spatial symmetries following femtosecond optical excitation in the prototypical type-I Weyl semimetal TaAs. Our results show that optically driven photocurrents can be tailored to explicitly break electronic symmetry in a generic fashion, opening up the possibility of driving phase transitions between symmetry-protected states on ultrafast timescales.

[Association between gestational blood pressure and pregnancy induced hypertension or pre-eclampsia]

Objective: To construct the gestational-age-specific blood pressure curve and percentile blood pressure values of pregnant women in Jiangsu Province, and to explore the clinic significance of the blood pressure changes in women whose blood pressure was less than 140/90 mmHg (1 mmHg=0.133 kPa) in each trimester and eventually developed pregnancy induced hypertension (PIH) or pre-eclampsia (PE). Methods: A prospective longitudinal cohort during pregnancy was built. Singleton pregnant women in the first trimester (11-13⁺⁶ weeks) were recruited from July 2017 to September 2020 in Nanjing Drum Tower Hospital, and were followed up in the second trimester (19-23⁺⁶ weeks), the third trimester (30-33⁺⁶ weeks) and approaching the expected date of delivery (35-38⁺⁶ weeks). The Viewpoint 6.0 software was used to record pregnancy-related information. The blood pressure was measured by standard methods in our clinic. Least mean square (LMS) function was performed to fit the gestational-age-specific blood pressure curve and percentile blood pressure values were calculated at every follow-up time point. Logistic regression was applied to calculate the OR for the groups with blood pressure ≥95th percentile (P₉₅). Results: There were 3 728 singleton pregnant women invited in this study, including 3 490 normal pregnant women (93.62%, 3 490/3 728), and 238 pregnant women with PIH or PE (6.38%, 238/3 728). Gestational-age-specific blood pressure curve showed that systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) decreased in the second trimester, compared with those in the first and the third trimester, however the fluctuation of blood pressure was low, but regardless of the gestational age, P₉₅ of SBP, DBP and MAP increased by 14, 11 and 11 mmHg respectively, compared with 50th percentile (P₅₀). In the first trimester, the risk of developing PIH or PE finally in pregnant women with blood pressure ≥P₉₅ was 4.36-fold (95%CI: 2.99-6.35) for SBP than women with SBP<P₉₅, 5.22-fold (95%CI: 3.65-7.46) for DBP and 5.14-fold (95%CI: 3.61-7.32) for MAP. When approaching the expected date of delivery, the corresponding risks of the women with blood pressure ≥P₉₅ were 16.76 times, 27.45 and 27.31 times respectively than those of the women with blood pressure <P₉₅. In the first trimester, every 1 mmHg elevation of SBP the risk developing PIH or PE increased by 24% (OR=1.24, 95%CI: 1.15-1.33), 44% (OR=1.44, 95%CI: 1.31-1.59) for DBP and 47% (OR=1.47, 95%CI: 1.33-1.61) for MAP, respectively. The risk in the second trimester was similar to that in the first trimester, and in the third trimester, the risk was further increased. When approaching the expected date of delivery, DBP or MAP increased by 1 mmHg, the risk developing PIH or PE was double; while SBP increased by 1 mmHg, the risk increased by 58%. The areas under the receiver operator characteristic curves of SBP, DBP and MAP were similar for predicting PIH or PE, and the predictive efficiency were all poor. Conclusions: Construction of percentile blood pressure values for pregnant women is helpful in identification of high-risk women of developing PIH or PE. The risk of PIH or PE in pregnant women with blood pressure ≥P₉₅ but <140/90 mmHg has significantly increased compared with women with blood pressure <P₉₅.

Skeleton Reorganization of Substituted Benzocyclobutenols through Rh-Catalyzed C-C Bond Cleavage Manipulated by Hydrogen Transfer

Although transition-metal-catalyzed C-C bond activation has been investigated extensively, C-C bond cleavage manipulated by hydrogen transfer has been unexplored. In this work, we disclose a skeleton reorganization of alkene-tethered benzocyclobutenols through Rh-catalyzed C-C bond cleavage coupled with intra- and intermolecular hydrogen transfer. The reaction pathway was well-tuned by the catalytic systems. As a result, divergent benzofurans bearing 4-β-hydroxy or 4-β-keto moieties were synthesized under pH- and redox-neutral conditions.

[Intrauterine balloon tamponade combined with temporary abdominal aortic balloon occlusion in the management of women with placenta accreta spectrum:a randomized controlled trial]

Objective: To access the effectiveness and safety of the intrauterine balloon tamponade verse gauze packing combined with temporary abdominal aortic balloon occlusion in the management of placenta accreta spectrum (PAS). Methods: This was an open-label, randomized controlled trial conducted in Nanjing Drum Tower Hospital. The patients suspected with PAS for uterine preservation surgery under the multidisciplinary team care were recruited between Aug 2015 and Jan 2018. When bleeding could not be achieved after fetus delivered, and a temporary abdominal aortic balloon occlusion and the compression sutures as needed, the women were randomly allocated 1∶1 into balloon tamponade (n=81) or gauze packing (n=80) group. The primary outcome was successful bleeding arrests by avoiding second line surgeries. The secondary outcomes included the volume of blood loss during and after cesarean section, the rate of PPH, incidence and amount of blood transfusion, hysterectomy, postpartum pain, ICU admission, need for re-laparotomy, and the length of hospital stay, readmission, and interventional radiology complications. Results: All the women [100% (81/81)] in the balloon group were obtained hemostasis without further intervention, significantly higher than 88% (70/80) in the gauze group (P=0.001). Before uterine tamponade, blood loss were 820 ml (620-1 230) ml and 850 ml (605-1 442) ml, while placenta bed were sutured in 96%（78/81, 77/80） respectively (P>0.05).The proportion of blood loss≥1 000 ml was higher in the gauze group than that in the balloon group (P=0.006). Maternal adverse events involving total blood loss, puerperal morbidity and postpartum pain occurred more frequently in the gauze group (P<0.05). The following outcome showed no statistically significant difference between the two groups: the vascular occlusion time, the dose of radiation, and interventional radiology complication (P>0.05). The median volume infused into the lower and upper balloons is 70 ml (50-100 ml) and 180 ml (100-240 ml). Conclusions: Incrauterine balloon tamponade is as effective as gauze packing in hemostasis following the placenta delivery in PAS. Compared with gauze packing, the uterine balloon tamponade is more effective.

miR-448-3p alleviates diabetic vascular dysfunction by inhibiting endothelial-mesenchymal transition through DPP-4 dysregulation

Diabetes mellitus (DM) often causes vascular endothelial damage and alters vascular microRNA (miR) expression. miR-448-3p has been reported to be involved in the development of DM, but whether miR-448-3p regulates diabetic vascular endothelial dysfunction remains unclear. To investigate the molecular mechanism of diabetic vascular endothelial dysfunction and the role of miR-448-3p therein, Sprague-Dawley rats were injected with streptozotocin (STZ) to establish diabetic animal model and the rat aortic endothelial cells were treated with high glucose to establish diabetic cell model. For the treatment group, after the induction of diabetes, the miR-448-3p levels in vivo and in vitro were upregulated by adeno-associated virus serotype 2 (AAV2)-miR-448-3p injection and miR-448-3p mimic transfection, respectively. Our results showed that AAV2-miR-448-3p injection alleviated the body weight loss and blood glucose level elevation induced by STZ injection. The miR-448-3p level was significantly decreased and the dipeptidyl peptidase-4 (DPP-4) messenger RNA level was increased in diabetic animal and cell models, which was reversed by miR-448-3p treatment. Moreover, the diabetic rats exhibited endothelial damage and endothelial-mesenchymal transition (EndMT), while AAV2-miR-448-3p injection relieved those situations. In vitro experiments demonstrated that miR-448-3p overexpression in endothelial cells alleviated endothelial damage by inhibiting EndMT through blocking the transforming growth factor-β/Smad pathway. We further proved that miR-448-3p negatively regulated DPP-4 by binding to its 3'-untranslated region, and DPP-4 overexpression reversed the effect of miR-448-3p overexpression on EndMT. Overall, we conclude that miR-448-3p overexpression inhibits EndMT via targeting DPP-4 and further ameliorates diabetic vascular endothelial dysfunction, indicating that miR-448-3p may serve as a promising therapeutic target for diabetic endothelial dysfunction.

Properties of Neon, Magnesium, and Silicon Primary Cosmic Rays Results from the Alpha Magnetic Spectrometer

We report the observation of new properties of primary cosmic rays, neon (Ne), magnesium (Mg), and silicon (Si), measured in the rigidity range 2.15 GV to 3.0 TV with 1.8×10^{6}  Ne, 2.2×10^{6}  Mg, and 1.6×10^{6}  Si nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. The Ne and Mg spectra have identical rigidity dependence above 3.65 GV. The three spectra have identical rigidity dependence above 86.5 GV, deviate from a single power law above 200 GV, and harden in an identical way. Unexpectedly, above 86.5 GV the rigidity dependence of primary cosmic rays Ne, Mg, and Si spectra is different from the rigidity dependence of primary cosmic rays He, C, and O. This shows that the Ne, Mg, and Si and He, C, and O are two different classes of primary cosmic rays.

Properties of Cosmic Helium Isotopes Measured by the Alpha Magnetic Spectrometer

Precision measurements by the Alpha Magnetic Spectrometer (AMS) on the International Space Station of ^{3}He and ^{4}He fluxes are presented. The measurements are based on 100 million ^{4}He nuclei in the rigidity range from 2.1 to 21 GV and 18 million ^{3}He from 1.9 to 15 GV collected from May 2011 to November 2017. We observed that the ^{3}He and ^{4}He fluxes exhibit nearly identical variations with time. The relative magnitude of the variations decreases with increasing rigidity. The rigidity dependence of the ^{3}He/^{4}He flux ratio is measured for the first time. Below 4 GV, the ^{3}He/^{4}He flux ratio was found to have a significant long-term time dependence. Above 4 GV, the ^{3}He/^{4}He flux ratio was found to be time independent, and its rigidity dependence is well described by a single power law ∝R^{Δ} with Δ=-0.294±0.004. Unexpectedly, this value is in agreement with the B/O and B/C spectral indices at high energies.

Scaling of the Fano Effect of the In-Plane Fe-As Phonon and the Superconducting Critical Temperature in Ba_{1-x}K_{x}Fe_{2}As_{2}

By means of infrared spectroscopy, we determine the temperature-doping phase diagram of the Fano effect for the in-plane Fe-As stretching mode in Ba_{1-x}K_{x}Fe_{2}As_{2}. The Fano parameter 1/q^{2}, which is a measure of the phonon coupling to the electronic particle-hole continuum, shows a remarkable sensitivity to the magnetic and structural orderings at low temperatures. Most strikingly, at elevated temperatures in the paramagnetic tetragonal state we observe a linear correlation between 1/q^{2} and the superconducting critical temperature T_{c}. Based on theoretical calculations and symmetry considerations, we identify the relevant interband transitions that are coupled to the Fe-As mode. In particular, we show that a sizable xy orbital component at the Fermi level is fundamental for the Fano effect and, thus, possibly also for the superconducting pairing.

Tracking Ultrafast Photocurrents in the Weyl Semimetal TaAs Using THz Emission Spectroscopy

We investigate polarization-dependent ultrafast photocurrents in the Weyl semimetal TaAs using terahertz (THz) emission spectroscopy. Our results reveal that highly directional, transient photocurrents are generated along the noncentrosymmetric c axis regardless of incident light polarization, while helicity-dependent photocurrents are excited within the ab plane. This is consistent with earlier static photocurrent experiments, and demonstrates on the basis of both the physical constraints imposed by symmetry and the temporal dynamics intrinsic to current generation and decay that optically induced photocurrents in TaAs are inherent to the underlying crystal symmetry of the transition metal monopnictide family of Weyl semimetals.

Towards Understanding the Origin of Cosmic-Ray Electrons

Precision results on cosmic-ray electrons are presented in the energy range from 0.5 GeV to 1.4 TeV based on 28.1×10^{6} electrons collected by the Alpha Magnetic Spectrometer on the International Space Station. In the entire energy range the electron and positron spectra have distinctly different magnitudes and energy dependences. The electron flux exhibits a significant excess starting from 42.1_{-5.2}^{+5.4}  GeV compared to the lower energy trends, but the nature of this excess is different from the positron flux excess above 25.2±1.8  GeV. Contrary to the positron flux, which has an exponential energy cutoff of 810_{-180}^{+310}  GeV, at the 5σ level the electron flux does not have an energy cutoff below 1.9 TeV. In the entire energy range the electron flux is well described by the sum of two power law components. The different behavior of the cosmic-ray electrons and positrons measured by the Alpha Magnetic Spectrometer is clear evidence that most high energy electrons originate from different sources than high energy positrons.

Towards Understanding the Origin of Cosmic-Ray Positrons

Precision measurements of cosmic ray positrons are presented up to 1 TeV based on 1.9 million positrons collected by the Alpha Magnetic Spectrometer on the International Space Station. The positron flux exhibits complex energy dependence. Its distinctive properties are (a) a significant excess starting from 25.2±1.8  GeV compared to the lower-energy, power-law trend, (b) a sharp dropoff above 284_{-64}^{+91}  GeV, (c) in the entire energy range the positron flux is well described by the sum of a term associated with the positrons produced in the collision of cosmic rays, which dominates at low energies, and a new source term of positrons, which dominates at high energies, and (d) a finite energy cutoff of the source term of E_{s}=810_{-180}^{+310}  GeV is established with a significance of more than 4σ. These experimental data on cosmic ray positrons show that, at high energies, they predominantly originate either from dark matter annihilation or from other astrophysical sources.

Temperature-Driven Topological Phase Transition and Intermediate Dirac Semimetal Phase in ZrTe_{5}

We present an infrared spectroscopy study of ZrTe_{5}, which confirms a recent theoretical proposal that this material exhibits a temperature-driven topological quantum phase transition from a weak to a strong topological insulating state with an intermediate Dirac semimetal state around T_{p}≃138  K. Our study details the temperature evolution of the energy gap in the bulk electronic structure. We found that the energy gap closes around T_{p}, where the optical response exhibits characteristic signatures of a Dirac semimetal state, i.e., a linear frequency-dependent optical conductivity extrapolating to the origin (after subtracting a weak Drude response). This finding allows us to reconcile previous diverging reports about the topological nature of ZrTe_{5} in terms of a variation of T_{p} that depends on the crystal growth condition.

Observation of Complex Time Structures in the Cosmic-Ray Electron and Positron Fluxes with the Alpha Magnetic Spectrometer on the International Space Station

We present high-statistics, precision measurements of the detailed time and energy dependence of the primary cosmic-ray electron flux and positron flux over 79 Bartels rotations from May 2011 to May 2017 in the energy range from 1 to 50 GeV. For the first time, the charge-sign dependent modulation during solar maximum has been investigated in detail by leptons alone. Based on 23.5×10^{6} events, we report the observation of short-term structures on the timescale of months coincident in both the electron flux and the positron flux. These structures are not visible in the e^{+}/e^{-} flux ratio. The precision measurements across the solar polarity reversal show that the ratio exhibits a smooth transition over 830±30 days from one value to another. The midpoint of the transition shows an energy dependent delay relative to the reversal and changes by 260±30 days from 1 to 6 GeV.

Precision Measurement of Cosmic-Ray Nitrogen and its Primary and Secondary Components with the Alpha Magnetic Spectrometer on the International Space Station

A precision measurement of the nitrogen flux with rigidity (momentum per unit charge) from 2.2 GV to 3.3 TV based on 2.2×10^{6} events is presented. The detailed rigidity dependence of the nitrogen flux spectral index is presented for the first time. The spectral index rapidly hardens at high rigidities and becomes identical to the spectral indices of primary He, C, and O cosmic rays above ∼700  GV. We observed that the nitrogen flux Φ_{N} can be presented as the sum of its primary component Φ_{N}^{P} and secondary component Φ_{N}^{S}, Φ_{N}=Φ_{N}^{P}+Φ_{N}^{S}, and we found Φ_{N} is well described by the weighted sum of the oxygen flux Φ_{O} (primary cosmic rays) and the boron flux Φ_{B} (secondary cosmic rays), with Φ_{N}^{P}=(0.090±0.002)×Φ_{O} and Φ_{N}^{S}=(0.62±0.02)×Φ_{B} over the entire rigidity range. This corresponds to a change of the contribution of the secondary cosmic ray component in the nitrogen flux from 70% at a few GV to <30% above 1 TV.

Observation of Fine Time Structures in the Cosmic Proton and Helium Fluxes with the Alpha Magnetic Spectrometer on the International Space Station

We present the precision measurement from May 2011 to May 2017 (79 Bartels rotations) of the proton fluxes at rigidities from 1 to 60 GV and the helium fluxes from 1.9 to 60 GV based on a total of 1×10^{9} events collected with the Alpha Magnetic Spectrometer aboard the International Space Station. This measurement is in solar cycle 24, which has the solar maximum in April 2014. We observed that, below 40 GV, the proton flux and the helium flux show nearly identical fine structures in both time and relative amplitude. The amplitudes of the flux structures decrease with increasing rigidity and vanish above 40 GV. The amplitudes of the structures are reduced during the time period, which started one year after solar maximum, when the proton and helium fluxes steadily increase. Above ∼3  GV the p/He flux ratio is time independent. We observed that below ∼3  GV the ratio has a long-term decrease coinciding with the period during which the fluxes start to rise.

Observation of New Properties of Secondary Cosmic Rays Lithium, Beryllium, and Boron by the Alpha Magnetic Spectrometer on the International Space Station

We report on the observation of new properties of secondary cosmic rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of 5.4×10^{6} nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of 2.0±0.1. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary cosmic rays has also been observed in the AMS measurement of primary cosmic rays He, C, and O but the rigidity dependences of primary cosmic rays and of secondary cosmic rays are distinctly different. In particular, above 200 GV, the secondary cosmic rays harden more than the primary cosmic rays.

Observation of the Identical Rigidity Dependence of He, C, and O Cosmic Rays at High Rigidities by the Alpha Magnetic Spectrometer on the International Space Station

We report the observation of new properties of primary cosmic rays He, C, and O measured in the rigidity (momentum/charge) range 2 GV to 3 TV with 90×10^{6} helium, 8.4×10^{6} carbon, and 7.0×10^{6} oxygen nuclei collected by the Alpha Magnetic Spectrometer (AMS) during the first five years of operation. Above 60 GV, these three spectra have identical rigidity dependence. They all deviate from a single power law above 200 GV and harden in an identical way.

Temperature-tunable Fano resonance induced by strong coupling between Weyl fermions and phonons in TaAs

Strong coupling between discrete phonon and continuous electron–hole pair excitations can induce a pronounced asymmetry in the phonon line shape, known as the Fano resonance. This effect has been observed in various systems. Here we reveal explicit evidence for strong coupling between an infrared-active phonon and electronic transitions near the Weyl points through the observation of a Fano resonance in the Weyl semimetal TaAs. The resulting asymmetry in the phonon line shape, conspicuous at low temperatures, diminishes continuously with increasing temperature. This behaviour originates from the suppression of electronic transitions near the Weyl points due to the decreasing occupation of electronic states below the Fermi level (E_F) with increasing temperature, as well as Pauli blocking caused by thermally excited electrons above E_F. Our findings not only elucidate the mechanism governing the tunable Fano resonance but also open a route for exploring exotic physical phenomena through phonon properties in Weyl semimetals.

The study of lattice vibrations coupled to electronic excitations may provide an avenue for exploring exotic physical phenomena. Here, Xu et al. observe a Fano resonance in the Weyl semimetal TaAs, revealing evidence for a strong coupling between phonons and Weyl fermions.

Precision Measurement of the Boron to Carbon Flux Ratio in Cosmic Rays from 1.9 GV to 2.6 TV with the Alpha Magnetic Spectrometer on the International Space Station

Knowledge of the rigidity dependence of the boron to carbon flux ratio (B/C) is important in understanding the propagation of cosmic rays. The precise measurement of the B/C ratio from 1.9 GV to 2.6 TV, based on 2.3 million boron and 8.3 million carbon nuclei collected by AMS during the first 5 years of operation, is presented. The detailed variation with rigidity of the B/C spectral index is reported for the first time. The B/C ratio does not show any significant structures in contrast to many cosmic ray models that require such structures at high rigidities. Remarkably, above 65 GV, the B/C ratio is well described by a single power law R^{Δ} with index Δ=-0.333±0.014(fit)±0.005(syst), in good agreement with the Kolmogorov theory of turbulence which predicts Δ=-1/3 asymptotically.

[Effect of snow sports on knee cartilage maturation in children and adolescent with MRI quantitative analysis Zhang]

Objective: To evaluate the effect of snow sports to the knee cartilage maturation of children and adolescent with quantitative analysis of 3.0 T MRI. Methods: Twenty children and adolescent who underwent snow sports training more than 6 months (11 males and 9 females) were recruited and named with sports group, and twenty children and adolescent who live regularly without any exercise (10 males and 10 females) were recruited as control group from June 2014 to June 2015.Each group was divided into subgroups according to their gender.Both groups were scanned by 3.0 T MR.According to the loading features of knee articular cartilage in snow sports, medial femoral condyle, lateral femoral condyle, medial tibial condyle and lateral tibial condyle were divided into subareas.T₂ values and cartilage thickness were measured in all areas. Results: The median ages of the sports group and control group were 14.2 and 13.6 years old, which showed no statistical difference between two groups.The BMI of the sports group and control group were 18.3 and 17.9 kg/m^2, which showed no statistical difference between two groups.Both in sports group and control group, the thickness and T₂ values of all areas showed significant differences between man and women in each group (all P<0.05). The cartilage thickness of sports group was higher than control group (P<0.05). The T₂ values showed no statistical difference in anterior central, posterior central of femoral condyles and anterior, central areas of tibial condyles between sports group and control group(P≥0.05). The T₂ values of anterior part of posterior femur and posterior areas of tibial condyle in sports group was higher than control group (P≥0.05). Conclusion: Gender difference may be an important effect factor of cartilage thickness. Scientific snow sports training maybe has positive influence for cartilage maturation of children and adolescent.

Antiproton Flux, Antiproton-to-Proton Flux Ratio, and Properties of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49×10^{5} antiproton events and 2.42×10^{9} proton events. The fluxes and flux ratios of charged elementary particles in cosmic rays are also presented. In the absolute rigidity range ∼60 to ∼500  GV, the antiproton p[over ¯], proton p, and positron e^{+} fluxes are found to have nearly identical rigidity dependence and the electron e^{-} flux exhibits a different rigidity dependence. Below 60 GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios each reaches a maximum. From ∼60 to ∼500  GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.

Diagnostic performance of anti-citrullinated protein/peptide antibodies in juvenile idiopathic arthritis

The prevalence rates of anti-citrullinated protein/peptide antibodies (ACPAs) were investigated in a cohort of juvenile idiopathic arthritis (JIA) patients, and their diagnostic performances were compared. ACPAs, including anti-cyclic citrullinated peptide IgG (anti-CCP), anti-CCP IgG/IgA (anti-CCP3.1), citrullinated recombinant rat filaggrin antibodies (CPA), anti-mutated citrullinated vimentin (anti-MCV), and antibodies to citrullinated human IgG-derived peptides (RA/CP), were measured in the sera from 81 JIA patients. Serum samples from 55 children with other joint diseases or viral infections and 49 healthy donors were tested as controls. Of the 81 JIA patients, 7 (8.6%), 8 (9.9%), 17 (21.0%), 23 (28.4%), and 18 (22.2%) were found to be positive for anti-CCP, anti-CCP3.1, CPA, anti-MCV, and RA/CP, respectively, with specificities of 98.1, 95.1, 93.3, 84.6, and 86.5%. Analysis by subtype revealed that 7/7 (100%) of RF-positive polyarticular JIA patients tested positive at high serum levels for anti-MCV or RA/CP, and 5/7 (71.4%) were positive for anti-CCP, anti- CCP3.1, or CPA (P < 0.001, compared with controls). Eighteen of 81 JIA patients demonstrated joint erosions on radiographs and erosive arthritis occurred more often in ACPAs positive patients (P < 0.01). Our findings indicate that although ACPAs are not satisfactory screening biomarkers for JIA due to low sensitivity, ACPA measurement can aid in diagnosing RF-positive polyarticular JIA and identifying JIA patients with severe bone involvement. The diagnostic performance of each ACPA in JIA is different, and the careful selection of assays is necessary.

Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station

Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.

Precision Measurement of the Proton Flux in Primary Cosmic Rays from Rigidity 1 GV to 1.8 TV with the Alpha Magnetic Spectrometer on the International Space Station

A precise measurement of the proton flux in primary cosmic rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is important in understanding the origin, acceleration, and propagation of cosmic rays. We present the detailed variation with rigidity of the flux spectral index for the first time. The spectral index progressively hardens at high rigidities.

Hidden T-linear scattering rate in Ba0.6K0.4Fe2As2 revealed by optical spectroscopy

The optical properties of Ba0.6K0.4Fe2As2 have been determined in the normal state for a number of temperatures over a wide frequency range. Two Drude terms, representing two groups of carriers with different scattering rates (1/τ), well describe the real part of the optical conductivity σ1(ω). A "broad" Drude component results in an incoherent background with a T-independent 1/τb, while a "narrow" Drude component reveals a T-linear 1/τn resulting in a resistivity ρn≡1/σ1n(ω→0) also linear in temperature. An arctan(T) low-frequency spectral weight is also strong evidence for a T-linear 1/τ. A comparison to other materials with similar behavior suggests that the T-linear 1/τn and ρn in Ba0.6K0.4Fe2As2 originate from scattering from spin fluctuations and hence that an antiferromagnetic quantum critical point is likely to exist in the superconducting dome.

A unique magnetic resonance imaging feature of glioblastoma multiforme: the 'pseudopalisade' sign

This study was designed to investigate the unique magnetic resonance imaging (MRI) appearance of histopathologically-proven glioblastoma multiforme (GBM) with pseudopalisade necrosis and to assess its value for grading gliomas and providing a differential diagnosis. The study included 169 patients with intracranial masses who underwent surgery and had a proven histopathological diagnosis: 50 with GBM, 77 with gliomas (46 grade II and 31 grade III) and 42 with other intracranial masses (20 metastases, 14 lymphomas and eight abscesses). All patients underwent preoperative brain MRI including post-contrast T(1)-weighted imaging. The presence of the 'pseudopalisade' sign on post-contrast T(1)-weighted images was compared among the different types of brain mass. The frequency of the 'pseudopalisade' sign in GBMs (94.00%) was significantly higher than that seen in grade II and III gliomas (11.69%) and other intracranial masses (7.14%). The 'pseudopalisade' sign on post-contrast T(1)-weighted images was useful for grading gliomas and for differentiating GBM from other brain masses.

Observation of a near-threshold enhancement in the pp mass spectrum from radiative J/psi-->gammapp decays

We observe a narrow enhancement near 2m(p) in the invariant mass spectrum of pp pairs from radiative J/psi-->gammapp decays. No similar structure is seen in J/psi-->pi(0)pp decays. The results are based on an analysis of a 58 x 10(6) event sample of J/psi decays accumulated with the BESII detector at the Beijing electron-positron collider. The enhancement can be fit with either an S- or P-wave Breit-Wigner resonance function. In the case of the S-wave fit, the peak mass is below 2m(p) at M=1859(+3)(-10) (stat)+5-25(syst) MeV/c(2) and the total width is Gamma<30 MeV/c(2) at the 90% confidence level. These mass and width values are not consistent with the properties of any known particle.

Tumor heterogeneity in small hepatocellular carcinoma: analysis of tumor cell proliferation, expression and mutation of p53 AND beta-catenin

Most hepatocellular carcinomas (HCCs) first occur as well-differentiated HCCs, from which poorly differentiated HCC cells develop because of dedifferentiation. In this study, we try to clarify the changes of dedifferentiation and cell proliferative activity and their relationship in small HCCs (less than 3.0 cm in diameter) and try to learn the mechanism of these changes by analysing the expressions and genetic changes of proliferation-related genes p53 and beta-catenin. Of 41 surgically resected small HCCs, 11 were identified to have tumor heterogeneity. DNA from the 11 small HCCs, consisting of 29 intratumoral lesions and 11 noncancerous liver tissues adjacent to HCCs, was extracted from paraffin embedded tissue sections. Exons 5-8 of p53 gene and exon 3 of beta-catenin gene were amplified by polymerase chain reaction and analyzed by direct sequence. The serial sections were also immunostained by anti-Ki-67, p53 and beta-catenin antibody. Immunohistochemistry showed that the p53 overexpression was significantly related to the proliferative activities as evaluated by Ki-67 immunostaining and to the histological differentiation. The expression of beta-catenin was found to be heterogeneously distributed not only in various histological grades of the same tumor but also in areas of the same histological grade. p53 and beta-catenin gene mutations were detected in 1 tumor respectively, both of which were second primary HCCs and also recurred later. The p53 mutation showed the same mutation pattern in heterogeneous subpopulations. beta-catenin mutation was detected only in the less differentiated lesion but not in the well-differentiated lesion of tumor. In conclusion, our findings suggest that there was histological heterogeneity in small but established HCC, which was accompanied by increased proliferative activity and p53 overexpression. The overexpression of beta-catenin may be related to the proliferative activity and dedifferentiation of HCC.

[AFP gene expression and antigenic protein localization in the cells of hepatocellular carcinoma and its surrounding tissues]

Using a double immunoenzymatic technique (PAP) and AFPcDNA-RNA in situ hybridization technique, we detected and analyzed the AFP gene expression and antigenic protein localization in hepatocellular carcinoma (HCC) and its surrounding tissues. The results demonstrated that AFP was truly synthesized again by some host liver cells around the cancer nodules. We considered that the cells which showed AFPmRNA positive hybridized signs might be a kind of preneoplastic cells. Their appearance might be related to injury caused by HBV infection and the inactivities of the inhibited gene on the AFP control mechanism. The substances secreted by the involved cancer cells, might be another causative factor for the excessive expression of the AFP in the liver cells near the cancer.