Abstract
PSR J2150+3427 is a 0.654 s pulsar discovered by the Commensal Radio Astronomy FAST Survey. From the follow-up observations, we find that the pulsar is in a highly eccentric orbit (
e
= ...0.601) with an orbital period of 10.592 days and a projected semimajor axis of 25.488 lt-s. Using 2.7 yr of timing data, we also measured the rate of periastron advance
ω
̇
= 0.0115(4) deg yr
−1
. An estimate for the total mass of the system using the
ω
̇
gives
M
tot
= 2.59(13)
M
⊙
, which is consistent with most of the known double neutron star (DNS) systems and one neutron star (NS)–white dwarf (WD) system named B2303+46. Combining
ω
̇
with the mass function of the system gives the masses of
M
p
< 1.67 and
M
c
> 0.98
M
⊙
for the pulsar and the companion star, respectively. This constraint, along with the spin period and orbital parameters, suggests that it is possibly a DNS system, and we cannot entirely rule out the possibility of an NS–WD system. Future timing observations will vastly improve the uncertainty in
ω
̇
, and are likely to allow the detection of additional relativistic effects, which can be used to modify the values of
M
p
and
M
c
. With a spin-down luminosity of
E
̇
= 5.07(6) × 10
29
erg s
−1
, PSR J2150+3427 is a very low-luminosity pulsar, with only the binary pulsar J2208+4610 having a smaller
E
̇
.
Abstract We report the timing analysis of PSR J1846−0513, a pulsar discovered by the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in Commensal Radio Astronomy FAST Survey. The pulsar ...possesses a spin period of 23.36 ms and a spin-down rate ( P ̇ ) of 1.0106(3) × 10 −18 s s −1 , and it is located in an eccentric orbit ( e ∼0.208) with an orbital period of 0.61 days. The characteristic age and surface magnetic field of the pulsar are found to be 366.62 Myr and 4.9178 × 10 9 G, respectively, indicating that it is a recycled pulsar. Using over two years of timing data, we measure the periastron advance ω ̇ = 0.8956(8) deg yr −1 . By assuming that this effect is purely relativistic, we have estimated the total mass M = 2.6287(35) M ⊙ and obtained an upper limit for the pulsar mass and a lower limit for the companion’s mass. Our results indicate that this is a double neutron star system.
A low-temperature heat pump sludge drying system was constructed and experimentally studied in the present study. The initial and final moisture contents on dry basis of sludge are 1.53 and 0.2, and ...the drying duration is 5 h. Theoretical models for heat pump circulation and moist air circulation are established and validated with the experimental results. Based on the validated theoretical models, sensitivity analysis of evaporating temperature, condensing temperature, and air mass flow rate on the temperature and humidity of moist air at the outlet of drying closet, drying rate and specific power consumption (SPC) are carried out. The temperature of moist air at the outlet of drying closet increases with increasing evaporating temperature and condensing temperature, while decreases with increasing air mass flow rate. The drying rate decreases with increasing evaporating temperature while increases with increasing condensing temperature, and first increases and then decreases with increasing air mass flow rate. The appreciated air mass flow rate ranges between 0.8 and 1.0 kg/s, and the drying rate around 6.0 kg/10min can be achieved under these conditions. The relative humidity of moist air at the outlet of drying closet shares a similar trend with the drying rate while SPC shows a contrary trend.
•A heat pump sludge drying system was designed, constructed and experimentally studied.•Theoretical models for circulations of heat pump and moist air are developed.•The coupling model is validated by the experimental data.•Sensitivity analysis of operating parameters is conducted.•Air mass flow rate ranging between 0.8 and 1.0 kg/s is suggested.
BACKGROUND AND PURPOSE The combination of Chinese herbs, Astragali Radix and Angelicae Sinensis Radix, could alleviate renal interstitial fibrosis. Astragaloside IV (AS‐IV) and ferulic acid (FA) are ...the two major active constituents in this combination. In this study, we employed rats with unilateral ureteral obstruction to determine whether AS‐IV and FA have the same renoprotective effects and investigated the mechanisms of this action.
EXPERIMENTAL APPROACH Renal pathological changes were evaluated after treatment with AS‐IV, FA or AS‐IV + FA (AF) for 10 days. Meanwhile, the expression of transforming growth factor β1 (TGF‐β1), fibronectin, α‐smooth muscle actin (α‐SMA), phosphorylation of c‐Jun NH2‐terminal kinase (p‐JNK) and nitric oxide (NO) production in kidney were determined. The expressions of fibronectin, α‐SMA, mitogen‐activated protein kinases JNK, extracellular signal‐regulated kinases (ERK), P38 in TGF‐β1‐treated NRK‐49F cells or interleukin‐1‐treated HK‐2 cells after AS‐IV, FA or AF were assessed.
KEY RESULTS AF alleviated the infiltration of mononuclear cells, tubular atrophy and interstitial fibrosis; reduced the expression of fibronectin, α‐SMA, TGF‐β1 and p‐JNK; and dramatically increased the production of NO in obstructed kidneys. Neither AS‐IV nor FA alone improved renal damage, but both increased NO production. AF inhibited α‐SMA and fibronectin expression in NRK‐49F or HK‐2 cells. Furthermore, AF significantly inhibited IL‐1β‐induced JNK phosphorylation, without affecting ERK or P38 phosphorylation. Neither AS‐IV nor FA alone had any effect on the cells.
CONCLUSIONS AND IMPLICATIONS AS‐IV synergizes with FA to alleviate renal tubulointerstitial fibrosis; this was associated with inhibition of tubular epithelial–mesenchymal transdifferentiation (EMT) and fibroblast activation, as well as an increase in NO production in the kidney.
ABSTRACT
We report the phase-connected timing ephemeris, polarization pulse profiles, Faraday rotation measurements, and Rotating-Vector-Model (RVM) fitting results of 12 millisecond pulsars (MSPs) ...discovered with the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in the Commensal Radio Astronomy FAST survey (CRAFTS). The timing campaigns were carried out with FAST and Arecibo over 3 yr. 11 of the 12 pulsars are in neutron star–white dwarf binary systems, with orbital periods between 2.4 and 100 d. 10 of them have spin periods, companion masses, and orbital eccentricities that are consistent with the theoretical expectations for MSP–Helium white dwarf (He WD) systems. The last binary pulsar (PSR J1912−0952) has a significantly smaller spin frequency and a smaller companion mass, the latter could be caused by a low orbital inclination for the system. Its orbital period of 29 d is well within the range of orbital periods where some MSP–He WD systems have shown anomalous eccentricities, however, the eccentricity of PSR J1912−0952 is typical of what one finds for the remaining MSP–He WD systems.
ABSTRACT
The follow-up timing observations were carried out for 24 pulsars discovered with the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in Commensal Radio Astronomy FAST Survey. ...We report their phase-connected timing ephemeris, polarization pulse profiles, and Faraday rotation measurements. With their spin periods spanning from 2.995 ms to 4.34 s, their period derivatives were determined to spread between 7.996(8) × 10−21 and 9.83(3) × 10−15 s s−1, which imply that they have characteristic ages from 1.97 × 106 to 5.93 × 109 yr. It is inferred that PSRs J0211+4235 and J0518+2431 are beyond the ‘traditional death line’. PSR J0211+4235 is beyond the ‘death valley’. The death line model of Zhang et al. also cannot explain the radio presence of PSR J0211+4235. This suggests that radiation theory needs to be improved. Besides, ten of the 22 canonical pulsars show nulling phenomena. Moreover, PSR J1617+1123 exhibits variation of emission and J0540+4542 shows subpulse drifting. The DM of five pulsars is larger than the estimated by the YMW16 electron density model, which could suggest that electron density models need updates for higher Galactic latitude regions. PSRs J0447+2447 and J1928−0548 are isolated millisecond pulsars. With their flux densities spanning from 5(1)–553(106) μJy, some of these new pulsars found by FAST are distant, dim, and low-$\dot{E}$ ones and are suitable for testing pulsar emission theories.
Abstract Background Congenital or acquired abnormalities may result in ureteral malformation, trauma, or defect. Traditional reconstructive methods are often associated with numerous complications. ...Tissue engineering technology may provide an alternate avenue for ureteral reconstruction. In this study, we constructed tissue-engineered tubularized grafts (TETGs) by seeding homologous adipose-derived stem cells (ADSCs) and bladder smooth muscle cells (SMCs) into bladder submucosa matrix (BSM) for ureteral reconstruction in rabbit models. Methods ADSCs and bladder SMCs were seeded onto 2 sides of the BSM, respectively. Then the grafts were used to construct TETGs of 4.0 cm length and 8.0 mm diameter and were transplanted into the omentum of rabbits for 2 weeks before ureteral reconstruction. The 4.0-cm segment of the ureter was replaced by the TETG. Evolutionary formation of tissue structures and degree of epithelization were evaluated with the use of histologic and immunohistochemical techniques at 2, 4, 8, and 16 weeks after implantation. Results All of the rabbits were alive until they were killed. Histologic and immunohistochemical analyses showed consistent regeneration of mature and functional urothelium. At 16 weeks after TETG implantation, multilayered urothelium covered the entire lumen, with visible neovascularization in the center and formation of organized smooth muscle bundles. Conclusions We successfully constructed a tissue-engineered transplanted graft by seeding ADSCs and SMCs onto the BSM for ureteral repair and reconstruction in a rabbit model.
Aristolochic acid nephropathy (AAN) is a worldwide problem and one of the common causes of chronic kidney disease (CKD) in China.
Three hundred patients diagnosed as AAN from 1997 to 2006 were ...enrolled. Medical histories of Chinese herb ingestion, clinical-pathological features and risk factors for renal failure were recorded. Patients were followed up for 2-156 months. Factors involved in the prognosis of AAN were investigated.
The 300 patients with AAN manifested three clinical subtypes, including acute kidney injury (acute AAN) in 13 patients, abrupt tubular dysfunction with normal serum creatinine (Scr) levels in seven cases and chronic tubulointerstitial nephropathy with decreased estimated glomerular filtration rate (eGFR) (chronic AAN) in 280 cases. The acute AAN cases had the highest aristolochic acid (AA)-I intake per day and developed progressive kidney failure during 1-7 years follow-up. The tubular dysfunction AAN patients had the lowest cumulative AA-I intake and were able to keep normal Scr levels during 2-8 years follow-up. The chronic AAN patients took the lowest AA-I dose per day but with the longest period and the highest cumulative dosage and exhibited a very large range of eGFR changing rate (from -21.6 to 5.2, median -3.5 mL/min/year). The cumulative AA-I intake (r = 0.330, P = 0.045) and the time course from the termination of AA medication to the start of follow-up (r = -0.430, P = 0.009) were found to be independent factors correlated with the decrease rate of eGFR in the chronic AAN patients. AA and the metabolites could be detected in a high frequency in patients who had stopped herbal medication for 1 year, which indicates a rather long washout time for these chemicals.
AAN has variant phenotypes with distinct prognosis, which is determined by the variable AA medications. With better understanding of toxic and environmental causes for kidney injury, there would be a better chance to uncover the causal factors of cases of 'CKD without known causes' which is crucial for improving the disease outcomes.
Three simple, controlled steps are all it takes to synthesize the title pentacene analogue DBTDT (see figure). The material's high ionization potential, high thermal and photostability, high ...mobilities, and an on/off ratio larger than 106 at a substrate temperature of ca. 36 °C, as reported here, suggest that DBTDT will be extremely valuable for applications in plastic organic electronics.
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