[A multi-center clinical retrospective study on the therapeutic effect of endoscopic myringoplasty]

Objective: To analyze the therapeutic effect of endoscopic myringoplasty. Methods: A retrospective analysis of 523 patients with chronic otitis media who underwent endoscopic myringoplasty between June 2016 and June 2017 in eight tertiary hospitals in China. Among all the patients, 256 were male and 267 were female, aged from 18 to 68 years old. The grafts used to repair the tympanic membrane were all tragus cartilage-perichondrium complex. All patients were followed up at 1 month, 3 months, 6 months, 9 months, and 12 months after surgery, at least 3 months. The closure rate of tympanic membrane perforation by different factors, the hearing results, and the incidence of postoperative complications were analyzed. SPSS 21.0 software was used to analyze the data. Results: Three months after operation, the closure rates of anterior, inferior, posterior and subtotal perforation were 92.4% (109/118), 94.9% (93/98), 95.6% (129/135), and 89.0% (153/172) respectively, the difference was not statistically significant (χ(2)=5.779, P=0.123). The closure rates of small, medium and large perforations were 100.0% (82/82), 93.7% (178/190) and 89.2% (224/251) respectively. The difference was statistically significant (χ(2)=10.927, P=0.004). The closure rates of dry ear and wet ear tympanic membrane perforation were 93.1% (392/421), 90.2% (92/102), the difference was not statistically significant (χ(2)=1.011, P=0.915). The preoperative pure tone audiometry(PTA) was (38.4±5.3) dBHL, while, the 3-month postoperative PTA was (25.1±5.7) dBHL. The difference was statistically significant (t=39.079, P<0.001). The preoperative air bone gap (ABG) was (22.4±4.3) dB, while 3 months postoperative ABG was (9.1±3.8) dB. The difference was statistically significant (t=53.004, P<0.001). Of all 523 patients, 14 (2.7%) had middle ear infection, 8 (1.5%) had dislocated tympanic membrane, 12 (2.3%) had parageusia, 35 (6.7%) had tinnitus, 28 (5.4%) had hearing loss, 26 (5.0%) had vertigo,33 (6.3%) had reperforation, 2 (0.4%) had secondary cholesteatoma, and none had facioplegia. Conclusions: Endoscopic myringoplasty is a safe and effective surgical method with good postoperative outcome.

[Children's non-carcinogenic health risk assessment of heavy metals exposure to residential indoor dust around an e-waste dismantling area in South China]

Objective: To evaluate the non-carcinogenic health risk of heavy metals (As, Cd, Cr, Cu, Mn, Pb and Zn) in residential indoor dust for young children around an e-waste dismantling area in South China. Methods: A village around an e-waste dismantling area in South China was selected as a research site in October 2016. Convenience sampling method was used to select 36 houses in the village and 36 dust samples were collected by vacuum cleaner. The concentrations of heavy metals (Cd, Cr, Cu, Mn, Pb and Zn) in each sample were determined and expressed by the average value. Non-carcinogenic health risk assessment was conducted using the US Environmental Protection Agency (EPA) Health Risk Assessment (HRA) model, the American Toxicology and Disease Registry (ATSDR) Target-organ Toxicity Dose (TTD) approach and the ATSDR Binary Weight-of-Evidence (BINWOE) model. Results: The mean ± SD of concentrations of As, Cd, Cr, Cu, Mn, Pb and Zn were (48.90±33.91), (5.95±3.89), (173.57±580.37), (412.71±1 190.00), (612.82±540.70), (297.41±293.22) and (1 052.81±1 156.48) mg/kg, respectively. The HI value of TTD (2.670) and BINWOE (2.933) were higher than the safety threshold of EPA recommended non-carcinogenic health risk. The HI value of TTD and BINWOE were 1.93 and 2.12 times higher than the HI value of HRA (1.386). Conclusion: There was non-carcinogenic health risk of heavy metals (As, Cd, Cr, Cu, Mn, Pb and Zn) via residential indoor dust around the e-waste dismantling area for local children.

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.

[Results of pars plana vitrectomy with peeling of the inner limiting membrane in patients with laser-induced macular hole]

Objective: To evaluate the results of pars plana vitrectomy (PPV) with peeling of the inner limiting membrane (ILM) in patients with laser-induced macular hole. Methods: The clinical data of 11 patients (12 eyes) with decreased visual acuity due to laser-induced macular hole from January 2014 to December 2017 were retrospectively studied.All patients underwent routine examination, fundus photography and optical coherence tomography (OCT). Patients were observed every two weeks. PPV with ILM peeling was performed when macular hole was enlarged. Closure of macular hole, pre- and post-operation visual acuity were observed. Results: A total of 11 male patients (12 eyes)aged (18±4) years were included in the study.Laser instruments which lead to macular hole consisted of laser toy (3 eye), laser pen (4 eye), laser torch (1 eye) and cosmetic laser instrument (4 eyes). All patients were followed up every two weeks and evaluated by OCT. None of the macular hole was spontaneously closed in this study. All Macular holes were enlarged in 1-3 months of follow-up and underwent PPV with ILM peeling immediately. All of the macular hole with PPV and ILM peeling were completely closed. During follow-up, the best-corrected visual acuity(BCVA) of 10 eyes (10/12) were found to increase above 3 lines and BCVA of 7 eyes(7/12) were found to be more than 0.5. Only 1 eye maintained the same visual acuity after the surgery which might be due to long course, large macular hole diameter (850 μm) and serious retinal pigment epithelium (RPE) damage. Conclusion: Early PPV with ILM peeling for laser induced macular hole might benefit for the closure rate of macular hole and better visual acuity prognosis.

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.

[Research Progress and Forensic Application on the Pathogenesis of Coronary Artery Spasm]

Coronary artery spasm （CAS） is a hyper-contraction of segmental coronary artery in response to multiple stimuli. At present, it's still in lack of specific diagnostic indicators of sudden cardiac death caused by CAS. This review summarizes current researches on the mechanisms of CAS and describes the roles of vascular endothelial dysfunction and vascular smooth muscle hypersensitivity in the course of CAS. Furthermore, the molecular mechanisms of the endogenous NO and endothelin-1 cause vascular endothelial dysfunction, and the phosphorylation of MLC2, Rho kinase and endoplasmic reticulum stress related to vascular smooth muscle hypersensitivity are discussed. Meanwhile, the possibility of forensic application for the related molecules on the diagnosis of sudden cardiac death caused by CAS are also explored.

Ultralow-Temperature Thermal Conductivity of the Kitaev Honeycomb Magnet α-RuCl_{3} across the Field-Induced Phase Transition

Recently, there have been increasingly hot debates on whether there exists a quantum spin liquid in the Kitaev honeycomb magnet α-RuCl_{3} in a high magnetic field. To investigate this issue, we perform ultralow-temperature thermal conductivity measurements on single crystals of α-RuCl_{3} down to 80 mK and up to 9 T. Our experiments clearly show a field-induced phase transition occurring at μ_{0}H_{c}≈7.5  T, above which the magnetic order is completely suppressed. The minimum of thermal conductivity at 7.5 T is attributed to the strong scattering of phonons by magnetic fluctuations. Most importantly, above 7.5 T, we do not observe any significant contribution of thermal conductivity from gapless magnetic excitations, which puts a strong constraint on the nature of the high-field phase of α-RuCl_{3}.

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.

[Clinical research of features of magnetic resonance imaging of high-voltage electrical burns in limbs at early stage]

Objective: To analyze the features of magnetic resonance imaging (MRI) of patients with high-voltage electrical burns in limbs at early stage. Methods: Thirty-eight patients with high-voltage electrical burns, conforming to the study criteria, were hospitalized in our unit from March 2013 to August 2016. T(1) weighted imaging (T(1)WI), T(2)WI, fat-suppression T(2)WI plain scan, and fat-suppression T(1)WI enhanced scan of MRI were performed in 78 limbs, including 56 upper limbs and 22 lower limbs at post injury hour 72. The MRI signal characteristics of electrical burns in skin and subcutaneous tissue, skeletal muscle, tendon, joint ligament, and skeleton of limbs were analyzed. " Sandwich-like" necrosis and injury in skeletal muscle, injuries of tendon, joint ligament, and skeleton were observed. MRI signal characteristics of amputated upper limbs and salvaged limbs were also analyzed. All patients underwent surgery within 24 h after MRI examination, and the muscle vitality was judged during operation. Muscle tissue without reaction to electrical stimulation which was completely necrotic as shown by MRI, muscle tissue with weak reaction to electrical stimulation which was injured with blood supply as shown by MRI, and muscle tissue with edema as shown by MRI were collected, and then the pathological characteristics of muscle tissue were observed with HE staining. Results: (1) The defect area of patients at entrance of current was bigger than that at exit. The skin and subcutaneous tissue extensively unevenly thickened. T(2)WI manifested hyperintensity, and T(1)WI manifested isointensity, while fat-suppression enhanced T(1)WI manifested uneven enhancement. Zonal effusion was seen in the region of serious subcutaneous edema. (2) For complete necrosis of skeletal muscle, T(2)WI manifested hypointense, isointensity, or slight hyperintensity, and T(1)WI manifested isointensity, slight hyperintensity, or mixed signal of isointensity and slight hyperintensity, while fat-suppression enhanced T(1)WI manifested most no enhancement area with clear boundary. The MRI signals of injured skeletal muscle could be divided into two types. Type Ⅰ signal was for partial necrotic muscle adjacent to the completely necrotic zone. T(2)WI manifested uneven hyperintensity or slight hyperintensity, with unclear boundary. T(1)WI manifested isointensity or slight hyperintensity. Fat-suppression enhanced T(1)WI manifested significant banding or laciness enhancement. Type Ⅱ signal was for deep muscle tissue far from the complete necrotic zone. T(2)WI manifested hyperintensity, and T(1)WI manifested isointensity or main isointensity mixed with hyperintensity, while fat-suppression enhanced T(1)WI manifested uneven moderate or slight enhancement. Normal muscle signal, type Ⅰ signal, and type Ⅱ signal were all mixed with necrotic signal, showing " sandwich-like" change. For skeletal muscle edema, T(2)WI manifested slight hyperintensity and unclear boundary, and T(1)WI manifested hypointense, while fat-suppression enhanced T(1)WI manifested no obvious enhancement. (3) For complete necrosis of tendon, T(2)WI manifested isointensity or slight hyperintensity, and T(1)WI manifested isointensity, while fat-suppression enhanced T(1)WI manifested no enhancement. For tendon injury, T(2)WI manifested isointensity, and T(1)WI manifested isointensity or hypointense, while fat-suppression enhanced T(1)WI manifested slight enhancement. (4) Severe injury of wrist joint were manifested as complete necrosis of soft tissue around joint. T(2)WI manifested slight hyperintensity or isointensity, and T(1)WI manifested isointensity, while fat-suppression enhanced T(1)WI manifested no enhancement or slightly uneven enhancement. For completely destroyed wrist joints, the structures were not clear from outside to inside. T(2)WI manifested slight hyperintensity or isointensity, and T(1)WI manifested hypointense or isointensity, while fat-suppression enhanced T(1)WI manifested no enhancement. For elbow injury, T(2)WI manifested hyperintensity, and T(1)WI manifested isointensity or hypointense, while fat-suppression enhanced T(1)WI manifested uneven enhancement. For knee injury, T(2)WI manifested hyperintensity, and T(1)WI manifested hypointense, while fat-suppression enhanced T(1)WI manifested slight enhancement. (5) For bone edema, T(2)WI manifested isointensity, while fat-suppression T(2)WI manifested slight hyperintensity. T(1)WI manifested isointensity, and fat-suppression enhanced T(1)WI manifested patchy enhancement. (6) MRI of amputated upper limbs showed necrosis signals, type Ⅰ signals, type Ⅱ signals, and mixed signals of type Ⅰ and type Ⅱ in skeletal muscle. The necrosis signal and type Ⅰ signal area of the distal end were more than 50% greater than those of the lesion. The scope of the ecological tissue was large and the boundary was not clear. There were diffuse injuries in both anterior and posterior muscles, and the ulnar and radial artery pulsation disappeared in the upper limbs. The MRI of salvaged limbs were type Ⅰ signal, type Ⅱ signal, mixed signals of type Ⅰ and type Ⅱ, and local necrosis signals of skeletal muscle. The type Ⅰ signal was the main type, and the distal end showed type Ⅱ signal. (7) For completely necrotic skeletal muscle as shown by MRI, surgical exploration showed loss of muscle viability, and pathological examination showed complete necrosis of striated muscle tissue. For injury area of skeletal muscle as shown by MRI, surgical exploration showed interecological muscle with activity worse than mormal muscle, and pathological examination showed normal muscle cells and muscle fiber mixed with necrotic striated muscle cells having karyopyknosis, with different degree of injury. For edema area of skeletal muscle as shown by MRI, surgical exploration showed swelling skeletal muscle and normal muscle vitality, and pathological examination showed striated muscle interstitial edema with a large number of inflammatory cells infiltration. The manifestions of MRI were consistent with the results of surgical exploration and pathological examination. Conclusions: Skeletal muscle complete necrosis, injury, and edema could be preferably differentiated by MRI, and the definite scope and depth of electrical injury, the injury of skin, tendon, joint ligament, and bone could also be displayed well on MRI. It can provide objective imaging basis for the diagnosis of high-voltage electrical burns in limbs at early stage, the establishment of clinical operation plan, and the judgment of intraoperative tissue vitality.

Expression of Mastoparan B, a Venom Peptide, Via Escherichia coli C43 (DE3) Coupled with an Artificial Oil Body-Cyanogen Bromide Technology Platform

BACKGROUND

Mastoparan B (MPB) is a venom peptide isolated from Vespa basalis (black-bellied hornet), one of the dangerous vespine wasps found in Taiwan. MPB is a tetradecapeptide (LKLKSIVSWAKKVL), amphiphilic venom peptide, with a molecular mass of 1.6 kDa. MPB belongs to an evolutionarily conserved component of the innate immune response against microbes. In this study, we attempted to modify a reliable oleosin-based fusion expression strategy coupled with the artificial oil body (AOB)-cyanogen bromide (CNBr) platform to produce bioactive MPB.

OBJECTIVES

The aim of this study was to develop an artificial oil body (AOB)-cyanogen bromide (CNBr) platform to produce the bioactive form of mastoparan B (MPB), which in a manner identical to that of its native counterpart.

METHODS

The plasmid pET30-His6-rOle(127M→L)-MPB was constructed, and then four different E. coli strains- BL21(DE3), BL21(DE3)pLysS, C41(DE3), and C43(DE3) were tested to identify the most suitable host for the pET30-His6-rOle(127M→L)-MPB fusion protein expression. We optimized the expression conditions by testing different growth temperatures, isopropyl-β-D-thiogalactoside (IPTG) concentrations, and post-induction collection times. Afterwards, the His6-rOle(127M→L)-MPB protein was purified by one-step nickel-chelated affinity chromatography (Ni2+-NTA) under denaturing conditions. The purified His6-rOle(127M→L)-MPB was selectively cleaved by thrombin protease to remove the His6-tag and the leader peptide from the N-terminus. Subsequently, rOle(127M→L)-MPB protein was constituted into AOB and incubated with CNBr for a cleavage reaction, which resulted in the release of the MPB from rOle(127M→L)-MPB protein via AOB. The purified MPB was identified by MALDI-MS and HPLC analysis, and its bioactivity was examined by antimicrobial testing.

RESULTS

After a 2-h induction period, the E. coli C43(DE3) was found to be superior to BL21(DE3) and the other protease-deficient strains as an expression host. And, the optimal His6-rOle(127M→L)-MPB expression at 37°C for 2 h after induction with 5 µM IPTG. The purified MPB showed that a single major peak was detected by HPLC/UV detection with a retention time of 22.5 minutes, which was approximately 90% pure. The putative MPB, and over two-third of the peptide sequence was verified by the MALDI-MS analysis. Finally, the purified MPB was examined by a broth dilution-antimicrobial susceptibility test. These results indicated that the purified MPB was bioactive and very effective in anti-bacterial (E. coli J96) activity. Here, we successfully used the oleosin-based fusion expression strategy coupled with the artificial oil body (AOB)-cyanogen bromide (CNBr) platform to produce bioactive MPB peptide which, in a manner identical to that of its native counterpart.

CONCLUSION

In this study, the recombinant oleosin based fusion strategy coupled with AOB-CNBr purification platform open a new avenue for the production of active MPB and facilitate the studies and applications of the peptide in the future for medicinal applications such as hypotension and antibacterial effect.

Establishment of 11 linked X-STR loci within 1.1 Mb to assist with kinship testing

This report identifies and characterizes 10 novel short tandem repeat (STR) loci on the human X chromosome, all of which are within a range of 1.1 Mb. These newly characterized loci were developed to aid in kinship assignment when the X chromosome is specifically required. The repeat DNA sequences were identified initially using data in GenBank and are located immediately upstream and downstream from the previously described locus DXS6807. Only those loci with seven or more observed alleles were used for further study resulting in the identification of 10 new loci. The distance between each pair of loci ranged from 24,998 to 244,701 bp with an average of approximately 110.8 kb. The number of observed alleles ranged from 7 to 30 for these 10 loci with a polymorphic information content ranging from 0.593 to 0.930. The LOD score from a pairwise linkage study ranged from 4.40 to 23.73, indicating that these 11 loci were highly linked, as expected. In line with standard forensic practice, all 11 loci can be amplified in one multiplex reaction, and comprehensive allelic ladders for all the loci have been constructed. These newly established 11 linked STR loci on the human X chromosome were found to be highly polymorphic and have the potential to aid in kinship testing where the X chromosome loci currently plays a role.

Absence of Magnetic Thermal Conductivity in the Quantum Spin-Liquid Candidate YbMgGaO_{4}

We present the ultralow-temperature specific heat and thermal conductivity measurements on single crystals of YbMgGaO_{4}, which was recently argued to be a promising candidate for a quantum spin liquid (QSL). In a zero magnetic field, a large magnetic contribution of specific heat is observed, and exhibits a power-law temperature dependence (C_{m}∼T^{0.74}). On the contrary, we do not observe any significant contribution of thermal conductivity from magnetic excitations. In magnetic fields H≥6  T, the exponential T dependence of C_{m} and the enhanced thermal conductivity indicate a magnon gap of the fully polarized state. The absence of magnetic thermal conductivity at the zero field in this QSL candidate puts a strong constraint on the theories of its ground state.

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.

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.

Investigation into length heteroplasmy in the mitochondrial DNA control region after treatment with bisulfite

We report on a method to analyze length heteroplasmy within the human mitochondrial genome in which there are polycytosine [poly(C)] stretches. These poly(C) tracts induce heteroplasmy with the resultant inherent problems of accurate sequence designations. In this study, 20 samples that exhibited length heteroplasmy due to variation in the C-tracts within hypervariable region I (HVI) were treated with bisulfite, and one or more cytosine bases in these C-tracts were converted randomly to uracil. This resulted in an accurate sequence designation for nearly all samples. The only exceptions in which the DNA sequence could still not be determined occurred when there was total conversion, or a lack of conversion, of the cytosine bases. Replicate tests on the same samples showed that individual cytosine bases were randomly converted to uracil. This simple method was useful for investigating length heteroplasmy due to 16189C and 310C transitions in the mitochondrial-DNA control region. It is valuable for medical and forensic investigations.

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.

Precision Measurement of the (e^{+}+e^{-}) Flux in Primary Cosmic Rays from 0.5 GeV to 1 TeV with the Alpha Magnetic Spectrometer on the International Space Station

We present a measurement of the cosmic ray (e^{+}+e^{-}) flux in the range 0.5 GeV to 1 TeV based on the analysis of 10.6 million (e^{+}+e^{-}) events collected by AMS. The statistics and the resolution of AMS provide a precision measurement of the flux. The flux is smooth and reveals new and distinct information. Above 30.2 GeV, the flux can be described by a single power law with a spectral index γ=-3.170±0.008(stat+syst)±0.008(energy scale).

Multidisciplinary predialysis education reduced the inpatient and total medical costs of the first 6 months of dialysis in incident hemodialysis patients

Background

The multidisciplinary pre-dialysis education (MPE) retards renal progression, reduce incidence of dialysis and mortality of CKD patients. However, the financial benefit of this intervention on patients starting hemodialysis has not yet been evaluated in prospective and randomized trial.

Methods

We studied the medical expenditure and utilization incurred in the first 6 months of dialysis initiation in 425 incident hemodialysis patients who were randomized into MPE and non-MPE groups before reaching end-stage renal disease. The content of the MPE was standardized in accordance with the National Kidney Foundation Dialysis Outcomes Quality Initiative guidelines.

Results

The mean age of study patients was 63.8±13.2 years, and 221 (49.7%) of them were men. The mean serum creatinine level and estimated glomerular filtration rate was 6.1±4.0 mg/dL and 7.6±2.9 mL⋅min⁻¹⋅1.73 m⁻², respectively, at dialysis initiation. MPE patients tended to have lower total medical cost in the first 6 months after hemodialysis initiation (9147.6±0.1 USD/patient vs. 11190.6±0.1 USD/patient, p = 0.003), fewer in numbers [0 (1) vs. 1 (2), p<0.001] and length of hospitalization [0 (15) vs. 8 (27) days, p<0.001], and also lower inpatient cost [0 (2617.4) vs. 1559,4 (5019.6) USD/patient, p<0.001] than non-MPE patients, principally owing to reduced cardiovascular hospitalization and vascular access–related surgeries. The decreased inpatient and total medical cost associated with MPE were independent of patients' demographic characteristics, concomitant disease, baseline biochemistry and use of double-lumen catheter at initiation of hemodialysis.

Conclusions

Participation of multidisciplinary education in pre-dialysis period was independently associated with reduction in the inpatient and total medical expenditures of the first 6 months post-dialysis owing to decreased inpatient service utilization secondary to cardiovascular causes and vascular access–related surgeries.

Trial Registration

ClinicalTrials.gov NCT00644046