[Network meta-analysis comparing the clinical outcomes and safety of robotic, laparoscopic, and transanal total rectal mesenteric resection for rectal cancer]

Objective: To methodically assess the clinical effectiveness and safety of robot-assisted total rectal mesenteric resection (RTME), laparoscopic-assisted total rectal mesenteric resection (laTME), and transanal total rectal mesenteric resection (taTME). Methods: A computer search was conducted on PubMed, Embase, Cochrane Library, and Ovid databases to identify English-language reports published between January 2017 and January 2022 that compared the clinical efficacy of the three surgical procedures of RTME, laTME, and taTME. The quality of the studies was evaluated using the NOS and JADAD scales for retrospective cohort studies and randomized controlled trials, respectively. Direct meta-analysis and reticulated meta-analysis were performed using Review Manager software and R software, respectively. Results: Twenty-nine publications comprising 8,339 patients with rectal cancer were ultimately included. The direct meta-analysis indicated that the length of hospital stay was longer after RTME than after taTME, whereas according to the reticulated meta-analysis the length of hospital stay was shorter after taTME than after laTME (MD=-0.86, 95%CI: -1.70 to -0.096, P=0.036). Moreover, the incidence of anastomotic leak was lower after taTME than after RTME (OR=0.60, 95%CI: 0.39 to 0.91, P=0.018). The incidence of intestinal obstruction was also lower after taTME than after RTME (OR=0.55, 95%CI: 0.31 to 0.94, P=0.037). All of these differences were statistically significant (all P<0.05). There were no statistically significant differences between the three surgical procedures regarding the number of lymph nodes cleared, length of the inferior rectal margin, or rate of positive circumferential margins (all P>0.05). An inconsistency test using nodal analysis revealed no statistically significant differences between the results of direct and indirect comparisons of the six outcome indicators (all P>0.05). Furthermore, we detected no significant overall inconsistency between direct and indirect evidence. Conclusion: taTME has advantages over RTME and laTME, in terms of radical and surgical short-term outcomes in patients with rectal cancer.

A preliminary study of peripheral T-cell subsets in porokeratosis patients with MVK or MVD variants

Background

Porokeratosis (PK) is considered a skin‐specific autoinflammatory keratinization disease. Intriguingly, four causative genes of PK are in turn arranged in mevalonate pathway, with MVD variants being the commonest followed by MVK variants in a cohort of Chinese patients. Evidence indicates that mevalonate metabolites induce trained immunity in human monocytes and regulate T cells at multiple levels. Of note, γδT cells are dually regulated by intracellular and extracellular mevalonate metabolism.

Aims

To identify the possible differences in T‐cell between MVK or MVD variants from PK patients.

Materials & Methods

Targeted exome sequencing and exonic CNV screening were performed in 26 patients with PK. Sanger sequencing was used to validate all identified variants. Among them, 22 patients were identified with MVK or MVD variants. PBMCs from 22 PK patients and 27 normal controls (NCs) were analysed by flow cytometry for the frequencies of T cells subsets, including IFN‐γ‐, and TNF‐α‐producing T cells.

Results

There were 14 mutations identified in the 26 PK patients, including 6 novel mutations (MVK: c.118_226+1337dup, c.388_392delGATATinsC, c.613A>T, c.768G>C, and MVD: c.250C>T, c.988T>G). In contrast to NCs, significantly decreased frequencies of CD8⁺ and Vγ9Vδ2 T cells were observed in the PK patients with MVD variants. Moreover, it was found that dysregulated secretion of pro‐inflammatory cytokines by T cells in both PK patients with MVK and MVD variants.

Conclusions

Our findings enriched the Human Gene Mutation Databases and showed probable differences in peripheral T cells subsets between PK patients and controls.

Superconductivity under pressure in the Dirac semimetal PdTe2

The Dirac semimetal PdTe₂ was recently reported to be a type-I superconductor (T _c   =  1.64 K, [Formula: see text] mT) with unusual superconductivity of the surface sheath. We here report a high-pressure study, [Formula: see text] GPa, of the superconducting phase diagram extracted from ac-susceptibility and transport measurements on single crystalline samples. T _c (p ) shows a pronounced non-monotonous variation with a maximum T _c   =  1.91 K around 0.91 GPa, followed by a gradual decrease to 1.27 K at 2.5 GPa. Surface superconductivity is robust under pressure as demonstrated by the large superconducting screening signal that persists for applied dc-fields [Formula: see text]. Surprisingly, for [Formula: see text] GPa the superconducting transition temperature at the surface [Formula: see text] is larger than T _c of the bulk. Therefore surface superconductivity may possibly have a non-trivial topological nature. We compare the measured pressure variation of T _c with recent results from band structure calculations and discuss the importance of a Van Hove singularity.

Atomic manipulation of the gap in Bi2Sr2CaCu2O8+x

Single-atom manipulation within doped correlated electron systems could help disentangle the influence of dopants, structural defects, and crystallographic characteristics on local electronic states. Unfortunately, the high diffusion barrier in these materials prevents conventional manipulation techniques. Here, we demonstrate the possibility to reversibly manipulate select sites in the optimally doped high-temperature superconductor Bi₂Sr₂CaCu₂O_8+x using the local electric field of the tip of a scanning tunneling microscope. We show that upon shifting individual Bi atoms at the surface, the spectral gap associated with superconductivity is seen to reversibly change by as much as 15 milli-electron volts (on average ~5% of the total gap size). Our toy model, which captures all observed characteristics, suggests that the electric field induces lateral movement of local pairing potentials in the CuO₂ plane.

Noisy defects in the high-Tc superconductor Bi2Sr2CaCu2O8+x

Dopants and impurities are crucial in shaping the ground state of host materials: semiconducting technology is based on their ability to donate or trap electrons, and they can even be used to transform insulators into high temperature superconductors. Due to limited time resolution, most atomic-scale studies of the latter materials focussed on the effect of dopants on the electronic properties averaged over time. Here, by using atomic-scale current-noise measurements in optimally doped Bi₂Sr₂CaCu₂O_8+x, we visualize sub-nanometre sized objects where the tunnelling current-noise is enhanced by at least an order of magnitude. We show that these objects are previously undetected oxygen dopants whose ionization and local environment leads to unconventional charge dynamics resulting in correlated tunnelling events. The ionization of these dopants opens up new routes to dynamically control doping at the atomic scale, enabling the direct visualization of local charging on e.g. high-T_c superconductivity.

The effects of dopants in high-temperature superconductors on the surrounding electronic structure give insights into their unconventional microscopic behaviour. Here the authors find a new class of defects that they identify as oxygen dopants whose ionization and local environment induce unusual atomic-scale charge dynamics.

Penetration depth study of the type-I superconductor PdTe2

Superconductivity in the topological non-trivial Dirac semimetal PdTe₂ was recently shown to be type-I. We hereby report measurements of the relative magnetic penetration depth, [Formula: see text], on several single crystals using a high precision tunnel diode oscillator technique. The temperature variation [Formula: see text] follows an exponential function for [Formula: see text], consistent with a fully-gapped superconducting state and weak or moderately coupling superconductivity. By fitting the data we extract a [Formula: see text]-value of  ∼500 nm. The normalized superfluid density is in good agreement with the computed curve for a type-I superconductor with nonlocal electrodynamics. Small steps are observed in [Formula: see text], which possibly relates to a locally lower [Formula: see text] due to defects in the single crystalline sample.

[Efficacy of Yisaipu tapering in the treatment of ankylosing spondylitis]

Objective: To assess the efficacy of Yisaipu tapering in patients with ankylosing spondylitis (AS). Methods: A total of 87 cases of AS patients from Guangdong Second Provincial General Hospital who were treated with Yisaipu and celecoxib were retrospectively analyzed from February 2013 to April 2017.All patients received full dose Yisaipu and celecoxib in the initial 12 weeks.After that, the patients in the full dose group maintained Yisaipu (50 mg/w) treatment from the 13(rd) to 24(th) week, while tapering group received Yisaipu 50 mg subcutaneous injection once every other week.By using AS disease activity score (ASDAS), Bath AS functional index (BASFI) and magnetic resonance (MR) score of sacroiliac joint (SIJ) plus recording adverse events, differences of efficacy and safety between groups were compared. Results: ASDAS and BASFI of tapering group were 1.1±0.7 and 1.3±1.1, while those of full dose group were 1.0±0.7 and 1.1±1.0, respectively.No significant difference of ASDAS or BASFI was found between groups.Besides, the MR scores of tapering and full dose groups were 8±7 and 8±6 respectively before therapy, while they were significantly lower in the 24(th) week (4±4 and 4±3, P<0.05). However, changes of MR score between groups were similar (P>0.05). Conclusion: Dose tapering of Yisaipu subcutaneous injection might be effective for keeping stable of disease activity and function in patients with AS.Its efficacy is similar to those of full dose Yisaipu.

Loss of cane and sugar yield resulting from Ceratovacuna lanigera Zehntner damage in cane-growing regions in China

Ceratovacuna lanigera Zehntner is a major leaf pest of sugarcane. Widely distributed, it affects both the yield and quality of sugarcane in China. This study aimed to assess real yield and sugar yield losses, and the effect of C. lanigera damage on emergence of newly planted and ratoon cane under current production levels. Field experiments were carried out from 2014 to 2016 in Yunnan Province China. At maturity, plants were harvested and weighed to determine yield, and the effect on sugarcane quality and sucrose content analyzed. Real yield decreased by average of 46,185 kg hm-2 (range: 37,545-61,845 kg hm-2) in damaged versus undamaged areas, with an average yield loss rate of 35.9% (28.5-45.7%). Juice yield decreased by an average of 3.01% (2.4-4.13%) and sucrose content by 6.38% (5.48-8.16%). Juice brix decreased by an average of 7.66°BX (6.95-9.05°BX) and juice gravity purity by 12.35% (8.43-19.97%). In contrast, the reducing sugar content increased by an average of 1.21% (1.01-1.3%). Emergence rates of newly planted cane decreased by an average of 26.0% (24.7-27.3%). The emergence number of ratoon cane decreased by 66,834 hm2 (57,429-76,238 hm-2) and relative emergence loss rates of ratoon cane decreased by an average of 57.8% (57.6-58.0%). These findings confirm that C. lanigera damage severely affects sugarcane yield and quality in Yunnan Province. The results will help the implementation of effective control measures, thereby supporting sustainable development of the Chinese sugar industry.

Macroscopic phase separation of superconductivity and ferromagnetism in Sr0.5Ce0.5FBiS2-x Se x revealed by μSR

The compound Sr_0.5Ce_0.5FBiS₂ belongs to the intensively studied family of layered BiS₂ superconductors. It attracts special attention because superconductivity at T_sc = 2.8 K was found to coexist with local-moment ferromagnetic order with a Curie temperature T_C = 7.5 K. Recently it was reported that upon replacing S by Se T_C drops and ferromagnetism becomes of an itinerant nature. At the same time T_sc increases and it was argued superconductivity coexists with itinerant ferromagnetism. Here we report a muon spin rotation and relaxation study (μSR) conducted to investigate the coexistence of superconductivity and ferromagnetic order in Sr_0.5Ce_0.5FBiS_2−xSe_x with x = 0.5 and 1.0. By inspecting the muon asymmetry function we find that both phases do not coexist on the microscopic scale, but occupy different sample volumes. For x = 0.5 and x = 1.0 we find a ferromagnetic volume fraction of ~8 % and ~30 % at T = 0.25 K, well below T_C = 3.4 K and T_C = 3.3 K, respectively. For x = 1.0 (T_sc = 2.9 K) the superconducting phase occupies most (~64 %) of the remaining sample volume, as shown by transverse field experiments that probe the Gaussian damping due to the vortex lattice. We conclude ferromagnetism and superconductivity are macroscopically phase separated.

Micro-metric electronic patterning of a topological band structure using a photon beam

In an ideal 3D topological insulator (TI), the bulk is insulating and the surface conducting due to the existence of metallic states that are localized on the surface; these are the topological surface states. Quaternary Bi-based compounds of Bi(2-x)Sb(x)Te(3-y)Se(y) with finely-tuned bulk stoichiometries are good candidates for realizing ideal 3D TI behavior due to their bulk insulating character. However, despite its insulating bulk in transport experiments, the surface region of Bi(2-x)Sb(x)Te(3-y)Se(y) crystals cleaved in ultrahigh vacuum also exhibits occupied states originating from the bulk conduction band. This is due to adsorbate-induced downward band-bending, a phenomenon known from other Bi-based 3D TIs. Here we show, using angle-resolved photoemission, how an EUV light beam of moderate flux can be used to exclude these topologically trivial states from the Fermi level of Bi1.46Sb0.54Te1.7Se1.3 single crystals, thereby re-establishing the purely topological character of the low lying electronic states of the system. We furthermore prove that this process is highly local in nature in this bulk-insulating TI, and are thus able to imprint structures in the spatial energy landscape at the surface. We illustrate this by 'writing' micron-sized letters in the Dirac point energy of the system.

Magnetic and superconducting phase diagram of the half-Heusler topological semimetal HoPdBi

We report a study of the magnetic and electronic properties of the non-centrosymmetric half-Heusler antiferromagnet HoPdBi (TN = 2.0 K). Magnetotransport measurements show HoPdBi has a semimetallic behavior with a carrier concentration n = 3.7 × 10(18) cm(-3) extracted from the Shubnikov-de Haas effect. The magnetic phase diagram in the field-temperature plane has been determined by transport, magnetization, and thermal expansion measurements: magnetic order is suppressed at BM ~ 3.6 T for T --> 0. Superconductivity with Tc ~ 1.9 K is found in the antiferromagnetic phase. Ac-susceptibility measurements provide solid evidence for bulk superconductivity below Tc = 0.75 K with a screening signal close to a volume fraction of 100%. The upper critical field shows an unusual linear temperature variation with Bc2(T --> 0) = 1.1 T. We also report electronic structure calculations that classify HoPdBi as a new topological semimetal, with a non-trivial band inversion of 0.25 eV.

First Report of Meloidogyne enterolobii on Carrot in China

Carrot (Daucus carota var. sativus) is one of the 10 most economically important vegetable crops in the world. Recently, stunted and yellowing carrots grown on sandy soil in several commercial fields were observed in Dongshan County, Fujian Province, China. Many round to irregular shaped lumps and swellings were present on the surface of tap and fibrous roots, often with secondary roots emerging from the galls on taproots. Severe infection caused short, stubby, forked taproots leading to losses in quality and marketability. Meloidogyne sp. females and egg masses were dissected from the galls. The perineal patterns from 20 females were oval shaped with moderate to high dorsal arches and mostly lacking obvious lateral lines. The second-stage juvenile mean body length (n = 20) was 416 (390 to 461) μm; lateral lips were large and triangular in face view; tail was thin and length was averaged 56.1 (49.8 to 62.1) μm, with a broad, bluntly rounded tip. These morphological characteristics matched the original description of M. enterolobii (5). Species identity was further explored by sequencing the mitochondrial DNA (mtDNA) region between COII and the lRNA genes using primers C2F3/MRH106 (GGTCAATGTTCAGAAATTTGTGG/AATTTCTAAAGACTTTTCTTA GT) (4). A DNA fragment of ~840 bp was obtained and the sequence (GenBank Accession No. KJ146864) was compared with those in GenBank using BLAST and was 100% identical to the sequences of M. enterolobii and M. mayaguensis, a synonym of M. enterolobii (4). Part of the rDNA spanning ITS1, 5.8S gene, ITS2 was amplified with primers V5367/26S (TTGATTACGTCCCTGCCCTTT/TTTCACTCGCCGTTACTAAGG) (3), and the sequence obtained (KJ146863) was 99 to 100% identical to sequences of M. enterolobii (KF418369.1, KF418370.1, JX024149.1, and JQ082448.1). For further confirmation, M. enterolobii specific primers Me-F/Me-R (AACTTTTGTGAAAGTGCCGCTG/TCAGTTCAGGCAGGATCAACC) (2) were used for amplification of the rDNA-IGS2 sequences of eight populations of the nematode from three localities. A 200-bp amplification product was produced by each population, whereas no product was amplified from control populations of M. incognita or M. javanica. A single product of ~320 bp was obtained using primers 63VNL/63VTH (GAAATTGCTTTATTGTTACTAAG/TAGCCACAGCAAAATAGTTTTC ) (1) from the mtDNA 63-bp repeat region for these populations, and the sequence (KJ146861) showed 100% identity with sequences of M. enterolobii (AJ421395.1, JF309159.1, and JF309160.1). Therefore, the population of Meloidogyne sp. on carrot was confirmed to be M. enterolobii. This nematode has been reported to infect more than 20 plant species belonging to seven families, including Annonaceae, Cucurbitaceae, Convolvulaceae, Fabaceae, Marantaceae, Myrtaceae, and Solanaceae in China. To our knowledge, this is the first report of infection of carrot by M. enterolobii and the first record of M. enterolobii parasitizing a plant in the family Apiaceae in China. M. enterolobii has been reported in Guangdong and Hainan provinces, China. This is the first report of M. enterolobii in Fujian Province, in southeast China. References: (1) V. C. Blok et al. Nematology 4:773, 2002. (2) H. Long et al. Acta Phytopathol. Sin. 36:109, 2006. (3) T. C. Vrain et al. Fundam. Appl. Nematol. 15:565, 1992. (4) J. Xu et al. Eur. J. Plant Pathol. 110:309, 2004. (5) B. Yang and J. D. Eisenback. J. Nematol. 15:381, 1983.

First Report of Smut of Saccharum arundinaceum Caused by Sporisorium sorghi in Yunnan, China

Saccharum arundinaceum (Retz.) is a wild species of S. officinarum with good resistance to pests, diseases, drought, cold, and infertile soils, and has favorable tillering potential (4). Hybridization of S. arundinaceum with sugarcane may enable favorable characteristics of S. arundinaceum to be exploited, broadening the genetic base of sugarcane breeding. In May 2009, symptoms of a disease were observed on plants of S. arundinaceum at the National Nursery of Sugarcane Germplasm Resources in Yunnan Province, China, on approximately 10% of 120 plants within three germplasm collections of S. arundinaceum. The initial symptom was dwarfing, resulting in the spike heading 1 to 2 months earlier than on healthy plants. As infection progressed, the spikelet of each diseased plant became full of the black, powdery mass of fungal spores enclosed in an off-white membrane. Finally, the entire spike became severely infected. A Sporisorium sp. was isolated from diseased spike tissues that were surface-sterilized with 70% alcohol, then with 0.1% mercury chloride, dipped in sterilized water three times for 3 min each time, dried on sterilized absorbent paper, and placed onto potato dextrose agar (PDA) at 27 ± 2°C in the dark. Nine fungal isolates were identified as Sporisorium sorghi Ehrenberg ex. Link based on sorus morphology as well as spore morphology and color (1). Sori were cylindrical or oval and 2.5 to 12.0 mm in diameter. Spores were spherical, light olive-brown or black, and 5.0 to 9.0 × 4.0 to 8.5 mm. Preliminary morphological identification of the fungus was confirmed by PCR assay using genomic DNA extracted from the mycelia of pure cultures of each of nine isolates, which generated a 750-bp amplified region of the internal transcribed spacer (ITS) region of rDNA using ITS1/ITS4 universal primers (3). The ITS region was then sequenced (GenBank Accession No. JX183795), and displayed 98% similarity with the ITS sequence of an isolate of S. sorghi from Sorghum bicolor from each of France (AF038828.1) and Germany (AY740021.1). A pathogenicity test was completed with the S. arundinaceum isolate of S. sorghi by spraying 20 ml of a spore suspension (10⁴ conidia/ml) onto each of 10 stems (2) of S. arundinaceum in a field in February 2010. The spore suspension was prepared from 30-day-old cultures growing on PDA. Stems were inoculated approximately 4 cm above the ground, where each stem was cut with sterilized shears. For the control treatment, each of 10 cut stems was inoculated with 20 ml of sterilized water. Three replications of 10 stems were used for each treatment. Approximately 3.5 months after inoculation, symptoms began to appear on 18 of the 30 stems (three replicates of 10 stems) inoculated with the S. sorghi spore suspension, when heading occurred on the stems. Five months later, each entire spike exhibited symptoms. No symptoms were observed on control spikes of stems inoculated with water. S. sorghi was reisolated onto PDA from the tissues of diseased spikes on inoculated stems, and the reisolates were identified by PCR assay using ITS1/ITS4 universal primers, as described above. S. sorghi was not isolated from the spike tissues of the control plants. To our knowledge, this is the first report of smut on S. arundinaceus caused by S. sorghi in Yunnan Province, China. References: (1) L. Guo. Flora Fungorum Sinicorum.12:51, 2000. (2) W. F. Li et al. Chinese Plant Prot. 34:127, 2008. (3) W. J. Lin et al. Chinese Agri. Sci. Bull. 23:293, 2007. (4) X. Lu et al. Southwest China J. Agric. Sci. 20:103, 2007.

Design and implementation of a versatile and variable-frequency piezoelectric coefficient measurement system

We present a simple but versatile piezoelectric coefficient measurement system, which can measure the longitudinal and transverse piezoelectric coefficients in the pressing and bending modes, respectively, at different applied forces and a wide range of frequencies. The functionality of this measurement system has been demonstrated on three samples, including a PbZr(0.52)Ti(0.48)O(3) (PZT) piezoelectric ceramic bulk, a ZnO thin film, and a laminated piezoelectric film sensor. The static longitudinal piezoelectric coefficients of the PZT bulk and the ZnO film are estimated to be around 210 and 8.1 pC/N, respectively. The static transverse piezoelectric coefficients of the ZnO film and the piezoelectric film sensor are determined to be, respectively, -0.284 and -0.031 C/m(2).

Superconductivity in the doped topological insulator Cu{x}Bi{2}Se{3} under high pressure

We report a high-pressure single crystal study of the topological superconductor Cu{x}Bi{2}Se{3}. Resistivity measurements under pressure show superconductivity is depressed smoothly. At the same time the metallic behavior is gradually lost. The upper-critical field data B{c2}(T) under pressure collapse onto a universal curve. The absence of Pauli limiting and the comparison of B{c2}(T) to a polar-state function point to spin-triplet superconductivity, but an anisotropic spin-singlet state cannot be discarded completely.

10 x 112Gb/s PDM-QPSK transmission over 5032 km in few-mode fibers

Few-mode fibers (FMFs) are used for the first time to transmit over 5000 km. Ten WDM channels with 50GHz channel spacing at 112 Gb/s per channel using PDM-QPSK are launched into the fundamental mode of the FMFs by splicing single-mode fibers directly to the FMFs. Even though few-mode fibers can support an additional spatial mode LP(11) at 1550 nm, the signal remains in the fundamental mode and does not experience mode coupling throughout fiber transmission. After each span the signal is collected by a second single-mode fiber which is also spliced to the FMF. Span loss is compensated by single-mode EDFAs before it is launched to the next FMF span. The lack of mode coupling ensures that the signal does not suffer any impairments that may result from differential mode delay or excess loss. Therefore the FMFs used in this "single-mode operation" have the same bandwidth as single-mode fibers. Experimental results verified that FMFs have the significant advantage of large core size which reduces the nonlinear impairments suffered by the signal. It is shown that FMFs with an effective area of 130 μm(2), have an optimum launch power 2 dB higher compared to standard single-mode fibers and as a result a 1.1 dB improvement in the Q-factor is obtained after 3000 km.

Enhancement of superconductivity near the ferromagnetic quantum critical point in UCoGe

We report a high-pressure single crystal study of the superconducting ferromagnet UCoGe. Measurements of the ac susceptibility and resistivity under pressures up to 2.2 GPa show ferromagnetism is smoothly depressed and vanishes at a critical pressure p(c) = 1.4 GPa. Near the ferromagnetic critical point superconductivity is enhanced. Upper-critical field measurements under pressure show B(c2)(0) attains remarkably large values, which provides solid evidence for spin-triplet superconductivity over the whole pressure range. The obtained p-T phase diagram reveals superconductivity is closely connected to a ferromagnetic quantum-critical point hidden under the superconducting "dome."

Unusual upper critical field of the ferromagnetic superconductor UCoGe

We report upper critical field B(c2)(T) measurements on a single-crystalline sample of the ferromagnetic superconductor UCoGe. B(c2)(0) obtained for fields applied along the orthorhombic axes exceeds the Pauli limit for B parallela,b and shows a strong anisotropy B(c2)(a) approximately B(c2)(b)>>B(c2)(c). This provides evidence for an equal-spin pairing state and a superconducting gap function of axial symmetry with point nodes along the c axis, which is also the direction of the uniaxial ferromagnetic moment m(0)=0.07micro(B). An unusual curvature or kink is observed in the temperature variation of B(c2) which possibly indicates UCoGe is a two-band ferromagnetic superconductor.

A novel method to make regenerable core-shell calcium-based sorbents

A sorbent having a calcium oxide core and a clay shell was prepared and shown to be capable of reusable applications in absorption and desorption processes for carbon dioxide. The novelty of this sorbent is that only calcium carbonate and clay are used for its preparation with water as a binder. A two-step granulation procedure is used to get the core and then another step to coat the shell layer with the clay powder. A repeated wet-and-dry procedure probably makes the core porous yet strong enough to serve as a sorbent. The pellet is then calcined at 1200 degrees C for 2h to reach its final structure. The core-shell pellets have an overall diameter of 4.4mm with average shell thickness of 0.45 mm, crush load of 35 N and attrition index of 0.035 wt%/h. These results indicate that the pellets will probably be capable of withstanding the stress in future applications. Carbon dioxide absorption at or below 300 degrees C showed a maximum weight gain of 38% for our pellets. Finally, desorption in nitrogen at 800 degrees C can restore the pellet to its original state and hence it is ready for re-use as a sorbent.

Aortic valve endocarditis presents as pseudoaneurysm of the superior mesenteric artery

Mycotic aneurysms are an important cause of morbidity and mortality in endocarditis despite advanced antibiotic therapy. Visceral artery aneurysms are uncommon and usually remain clinically silent until rupture. We now report a case of successful surgical treatment of a superior mesenteric mycotic aneurysm of the superior mesenteric artery, followed by a review of pertinent clinical information.

Evaluation of the hepatic and renal-protective effects of Ganoderma lucidum in mice

The antioxidative effect of hot water extract of the mushroom Ganoderma lucidum on ethanol-induced free radical generation had been studied. In order to further investigate the hepatic and renal protective mechanism of Ganoderma lucidum, rates of lipid peroxidation were determined. The hot water extract of Ganoderma lucidum dose-dependently exhibited antioxidative effect on mouse liver and kidney lipid peroxidation; our results indicated that hepatic and renal homogenates have a higher malonic dialdehyde level in an ethanol administered group than in the Ganoderma lucidum treated group. It was concluded that the hepatic and renal protective mechanism of Ganoderma lucidum, might be due at least in part to its prominent superoxide scavenging effect. Ganoderma extract could protect the liver and kidney from superoxide induced hepatic and renal damages.

Recombinant hepatitis E virus genomes infectious for primates: importance of capping and discovery of a cis-reactive element

Hepatitis E virus recombinant genomes transcribed in vitro from two cDNA clones differing by two nucleotides were infectious for chimpanzees. However, one cDNA clone encoded a virus that was attenuated for chimpanzees and unable to infect rhesus monkeys. The second cDNA clone encoded a virus that infected both chimpanzees and rhesus monkeys and caused acute hepatitis in both. One mutation differentiating the two clones identified a cis-reactive element that appeared to overlap the 3' end of the capsid gene and part of the 3' noncoding region. Capping of the RNA transcripts was essential for infectivity.

Significance of glutamate and dopamine neurons in the ventral pallidum in the expression of behavioral sensitization to amphetamine

To explore the significance of ventral pallidum (VP) during the amphetamine sensitization, we first investigated if there are neurochemical alterations in the VP during amphetamine withdrawal period. Chronic amphetamine-treated (5 mg/kg x 14 days) rats displayed an apparent locomotion sensitization as compared with saline controls when challenged with 2 mg/kg amphetamine at withdrawal days 10-14. A microdialysis analysis revealed that output of the dopamine metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid, in the VP of amphetamine-sensitized rats increased approximately two-fold as compared to controls at both pre- and post-amphetamine challenge period. On the other hand, the in vivo glutamate output in the VP increased upon amphetamine challenge in the behaviorally sensitized rats, but not in the controls. To evaluate if drug manipulation in the VP would affect the behavioral sensitization, we treated both groups of rats with NMDA receptor antagonist, MK-801 (5 microg/microl for 5 days; bilateral) in the VP during withdrawal days 6-10. Animals were challenged with 2 mg/kg amphetamine at withdrawal day 11. The behavioral profile exhibited that MK-801 pre-treatment significantly blocked the locomotion hyperactivity in amphetamine-sensitized rats. Taken together, the current results suggest that the excitatory amino acid in the VP plays a significant role during the expression of behavioral sensitization to amphetamine.

Molecular basis for differing antineurogenic effects of GATA-1a and GATA-1b in Xenopus

The erythroid transcription factor GATA-1 in Xenopus has been cloned as a pair of presumably duplicated genes designated as xGATA-1a and xGATA-1b. Although both xGATA-1a and xGATA-1b are able to stimulate erythropoiesis, only xGATA-1b is capable of inhibiting neurogenesis in Xenopus embryos. Chimeras of these two genes were constructed by permuting coding and untranslated regions (UTR) on both ends of these two xGATA-1, and their neurogenesis-inhibitory effects were studied. These results reveal that (1) sequence variations between the coding regions alone do not account for the neurogenesis effect; (2) 3' UTR of xGATA-1a causes the loss of the neurogenesis inhibition of xGATA-1b; (3) 3' UTR of xGATA-1b is essential to inhibit neurogenesis. In addition, the presence of either UTR does not affect the stability of the mRNA in vitro. These observations suggest the influence of 3' UTR in xGATA-1 on the inhibition of neurogenesis.

Neuropeptide FF potentiates the behavioral sensitization to amphetamine and alters the levels of neurotransmitters in the medial prefrontal cortex

We have demonstrated that chronic administration of neuropeptide FF (NPFF) into the lateral ventricle potentiated the behavioral sensitization to amphetamine. Further, the treatment with NPFF decreased the levels of serotonin, and increased the glutamate and GABA content in the medial prefrontal cortex of amphetamine-sensitized rats. The results suggest that NPFF may modulate the neuronal process of amphetamine addiction.

Hepatitis A viruses with deletions in the 2A gene are infectious in cultured cells and marmosets

The 2A gene of hepatitis A virus (HAV) bears no obvious similarity to the corresponding genes of other picornaviruses and has no known function. In a preliminary effort to gain information about the HAV 2A gene product, we constructed several HAV cDNAs containing deletions of 30 or 45 nucleotides in the predicted central portion of the 2A gene. These deletions did not affect the sites of protein processing, although the rates or efficiencies of polyprotein cleavage at the surrounding cleavage junctions appeared slightly reduced. Transfection of FRhK-4 cells with RNA transcripts of the deleted HAV cDNAs generated small foci of infected cells and produced infectious virus that retained the deletion mutations. In contrast, a single amino acid insertion in the 2B coding region was lethal to virus replication despite normal protein processing. Another deletion, which included the predicted 2A/2B junction and extended into the 2B coding sequence, did not support polyprotein processing or generate viable virus. One of the viable internal 2A deletions was introduced into a wild-type HAV cDNA background, and transcripts were tested for infectivity by inoculation directly into the livers of two marmosets. Both animals seroconverted, displayed elevated serum liver enzymes, and excreted infectious virus. Thus, deletion of 10 or 15 amino acid residues from the predicted central portion of the 2A protein was tolerated with only relatively minor effects on the growth of HAV in cultured cells and in marmoset liver.

2B and 2C mutations are essential but mutations throughout the genome of HAV contribute to adaptation to cell culture

Chimeric viruses constructed from various portions of two infectious cDNA clones representing the genomes of the wild-type and cell culture-adapted mutants of the HM-175 strain of hepatitis A virus were compared for their ability to replicate in cultures of fetal rhesus kidney cells. Mutations located in either the 5' or 3' third of the genome could markedly enhance growth in vitro but only when they were combined with mutations in the P2 region within either the 2B or the 2C gene. Therefore, mutations in 2B and 2C are essential for cell culture adaptation but mutations elsewhere in the genome also contribute significantly to the enhanced growth rate.

Mutations in both the 2B and 2C genes of hepatitis A virus are involved in adaptation to growth in cell culture

Oligonucleotide-directed mutagenesis of an infectious cDNA clone of wild-type hepatitis A virus was performed to determine which mutations acquired in the nonstructural 2B and 2C genes during adaptation to growth in cell culture were effective in enhancing virus growth in vitro. Results of transfection assays demonstrated that one mutation in the 2B gene and two mutations in the 2C gene were responsible for an increased efficiency in growth, but growth enhancement required the participation of at least two of the three mutations.

Molecular basis of virulence and growth of hepatitis A virus in cell culture

The ability of engineering variants of hepatitis A virus (strain HM175) to replicate in cell culture or to cause disease in marmosets was evaluated. Virus variants were encoded by chimeric genomes constructed from infectious cDNA clones of two viruses (wild type and cell-culture-adapted) which differed in their ability to grow in vitro and to cause acute hepatitis in marmosets. Transfection and infectivity assays indicated that virus growth in vitro could be enhanced by subcloning the cell substrate prior to infection or by introducing multiple combinations of two or more mutations into the wild type genome. Various chimeric viruses induced liver enzyme elevations in marmosets, indicating that attenuation of virulence also required multiple mutations.

Purification of a factor capable of stimulating the guanine nucleotide exchange reaction of ras proteins and its effect on ras-related small molecular mass G proteins

We have previously identified a membrane factor capable of stimulating guanine nucleotide exchange activity for ras p21 proteins. The ras guanine nucleotide exchange factor (rGEF) was purified from bovine brain to near homogeneity by successive chromatographies on DE52 DEAE-cellulose, Sepharose 6B, hydroxylapatite, and FPLC phenyl-Superose resins. SDS/polyacrylamide gel electrophoresis of the purified rGEF showed a single major protein with a molecular mass of 35 kDa. rGEF increased the exchange rate of GDP in normal [Gly12]p21 or oncogenic [Val12]p21 up to 30- to 40-fold under physiological concentrations of Mg2+. Since the factor was free from GDP/GTP binding activity and nonspecific GDP hydrolytic activity, we propose that rGEF may regulate GDP/GTP exchange reaction of ras proteins in response to external growth signals. Moreover, rGEF enhanced the dissociation of bound GDP from some of ras-like G proteins, R-ras, rap1-A, rab1-B, and rho proteins, raising the possibility that rGEF may affect the activities of these proteins.

Hemodynamic effects of the intraventricular administration of angiotensin II and renin in awake dogs

This study was undertaken to investigate the hemodynamic changes induced by intraventricular injections of angiotensin II (A-II), 1 to 100 ng/kg/min, and renin in doses of 0.025 to 0.3 units (u) in conscious instrumented dogs. Angiotensin II produced a dose-related increase in mean arterial pressure; however, only the highest dose produced a significant increase of 23 +/- 6 mmHg. In contrast, renin did not significantly alter mean arterial pressure in the doses administered but 0.1 and 0.3 u induced a significant increase in systolic arterial blood pressure of 10 +/- 2 and 17 +/- 4 mmHg, respectively. Neither A-II nor renin affected heart rate, dP/dt or carotid, coronary or renal blood flows. These data suggest that in conscious dogs, the threshold level of A-II necessary to induce substantial hemodynamic changes is greater than the amount of A-II that can be acutely generated by activation of angiotensinogen. In addition, the present data suggest that the magnitude of the response is dependent on the availability of the substrate rather than the dose of renin injected centrally into conscious dogs.

A simple isolation method for basal-lateral plasma membranes from rat kidney cortex

Basal-lateral membranes were separated in a self-orienting Percoll (modified colloidal silica) gradient from a heavy microsomal membrane fraction by centrifugation at 48,000g for 0.5 h. The (Na+--K+)-ATPase activity as a marker enzyme for the basal-lateral plasma membrane was 20-fold enriched by this procedure. The adenylate-cyclase activity measured in the basal-lateral membrane fraction was stimulated 6-fold by parathyrin and only up to 1.5-fold by arginine-vasopressin, calcitonin, or isoproterenol. The yield of basal-lateral plasma membranes was 5 to 10 percent of the amount initially present in the homogenate. The method is also applicable to the pig kidney.