Optical Excitation and Trapping of

We have realized optical excitation, trapping, and detection of the radioisotope ^{81}Kr with an isotopic abundance of 0.9 ppt. The 124 nm light needed for the production of metastable atoms is generated by a resonant discharge lamp. Photon transport through the optically thick krypton gas inside the lamp is simulated and optimized to enhance both brightness and resonance. We achieve a state-of-the-art ^{81}Kr loading rate of 1800 atoms/h, which can be further scaled up by adding more lamps. The all-optical approach overcomes the limitations on precision and sample size of radiokrypton dating, enabling new applications in the earth sciences, particularly for dating of polar ice cores.

[Study on the deposition of monosodium urate in patients with first-episode of acute gouty arthritis by dual energy CT].

Objectives: To investigate the characteristics of monosodium urate (MSU) deposition in patients with the first-episode of acute gouty arthritis (Gout) by using dual energy CT (DECT) imaging technique. Methods: A total of 70 first-episode patients with acute Gout diagnosed in Peking University Third Hospital in 2019 were collected as the case group, including 69 males and 1 female, aged 17-65 (39±14) years. During the same period, a total of 15 male patients aged 19-56 (33±12) years were collected as the control group. They were admitted to the hospital due to sports injuries and were excluded from gout. The DECT data of the first-affected or the most painful joints of gout in the case group and the surgical ankle joints in the control group were retrospectively analyzed. The crystal morphology, volume and deposition location of MSU in the measured joints were evaluated and recorded, and the degree of MSU deposition in the joints of the first-episode patients with Gout and its coincidence with clinical symptoms were summarized. The χ(2) test, and Kruskal-walls were used for statistical analysis. Results: The detection rate of MSU by DECT in the case group was 97.1% (68/70), and 0 in the control group. The first-affected joints of Gout included 52 cases of ankles (74.3%), 13 cases of knees (18.6%), and 5 cases of wrists (7.1%). The three joints were mainly deposited with scattered submillimeter MCU. There was no significant difference in MSU morphology and volume between the three joints. The locations with the most MCU deposits among the three joints were 78.8% (41/52) of the posterior calf tendons (including Achilles tendon), 76.9% (10/15) of the knee articular cartilages, and 60.0% (3/5) of the palmaris tendons, while the distribution of the first metatarsophalangeal joint was less than 13.5% (7/52). The number of MSU deposited joints detected by DECT was 37 cases more than that of symptomatic joints, accounting for 52.8%. Conclusions: DECT is highly sensitive in detecting MCU in the first-episode of acute Gout, which helps to improve the early diagnosis rate of gout.

A preliminary study of biological characteristics of Streptococcus oligofermentans in oral microecology.

This study was designed to explore the biological characteristics of a new oral streptococcus species Streptococcus oligofermentans. Plaque samples were collected from caries-free and caries-active subjects. S. oligofermentans was selectively grown on Mitis salivarius agar plates and identified by using 2-step PCR and was isolated from 38% of 18 subjects. Isolates were found mostly on healthy tooth surfaces. S. oligofermentans had weaker abilities in acid production and demineralizing hydroxyapatite. When Streptococcus mutans was coincubated with S. oligofermentans, total number, acid production and calcium release were significantly inhibited. In conclusion, inhibition of S. mutans could be a beneficial biological characteristic of S. oligofermentans in oral microecology.

Real-time imaging and detection of intracranial haemorrhage by electrical impedance tomography in a piglet model.

The aim of this study was to use electrical impedance tomography (EIT) to detect and image acute intracranial haemorrhage (ICH) in an animal model. Blood was infused into the frontal lobe of the brains of anaesthetized piglets and impedance was measured using 16 electrodes placed in a circle on the scalp. The EIT images were constructed using a filtered back-projection algorithm. The mean of all the pixel intensities within a region of interest--the mean resistivity value (MRV)--was used to evaluate the relative impedance changes in the target region. A symmetrical index (SI), reflecting the relative impedance on both sides of the brain, was also calculated. Changes in MRV and SI were associated with the injection of blood, demonstrating that EIT can successfully detect ICH in this animal model. The unique features of EIT may be beneficial for diagnosing ICH early in patients after cranial surgery, thereby reducing the risk of complications and mortality.

Antidepressant effects of Kai-Xin-San in fluoxetine-resistant depression rats.

This study aimed to investigate the antidepressant effect and the mechanism of action of Kai-Xin-San (KXS) in fluoxetine-resistant depressive (FRD) rats. Two hundred male Wistar rats weighing 200±10 g were exposed to chronic and unpredictable mild stresses (CUMS) for 4 weeks and given fluoxetine treatment simultaneously. The rats that did not show significant improvement in behavioral indexes were chosen as the FRD model rats. These rats were randomly divided into four groups: FRD model control; oral fluoxetine and aspirin; oral KXS at a dose of 338 mg·kg-1·day-1; and oral KXS at a dose of 676 mg·kg-1·day-1. Rats continued to be exposed to CUMS and underwent treatment once a day for 3 weeks, then cytokine (COX-2, IFN-γ, IL-1ß, IL-2, IL-4, IL-6, IL-10, TGF-ß, and TNF-α) levels in the hippocampus and serum, and organ coefficients were measured. Both doses of KXS improved the crossing and rearing frequencies, sucrose-preference index, and body weight in FRD rats. KXS at a dose of 338 mg·kg-1·day-1reduced COX-2, IL-2, IL-6, TNF-α levels, increased IL-10 level in the hippocampus, and reduced IL-2 and TNF-α levels in serum. KXS at a dose of 676 mg·kg-1·day-1reduced TNF-α level in the hippocampus, reduced IL-2 and TNF-α levels in serum, and increased IFN-γ and IL-10 levels in the hippocampus and serum. There were no significant differences in organ-coefficients of the spleen among and between groups. The results suggested that oral administration of KXS in FRD rats was effective in improving behavior disorders by influencing various inflammatory pathways.

First isolation of Xanthomonas campestris from the blood of a Chinese woman.

Xanthomonas campestris isolated from the blood of a patient with a fever was first reported. Xanthomonas campestris is a bacterium that can cause black rot of some vegetables, such as rape. Chinese cabbage, etc. Human infection due to X. campestris has not been reported so far. The characteristics of this organism, including morphology, staining, physiology and biochemistry were studied. We believe that X. campestris is also one of the opportunistic pathogens, which can infect compromised host.

[Design of the system for detecting impedance cardiography based on windows plantform].

In this paper is introduced systematically the design of the system for detecting impedance cardiography (ICG) based on Windows plantform. The three major ICG indexes of 30 students have been detected by the designed system in the clinical application, and conform with the results from the reference. On the other hand, compared with the system based on DOS plantform, the system has higher detection speed, and becomes more convenient, more flexible by the introduction of Mouse.

[The study on non-contact detection of breathing and heartbeat based on radar principles].

The paper introduces the design of hardware and software of non-contact detection system for breathing and heartbeat in human body with radar principles and technology. The detection technology is discussed. Under conditions of the illuminating power P < 1 mW and the distance S < 10 m, the non-contact breathing and heartbeat measurement, can be in different positions and with different clothing on the subject. The results show that the system with the technology has a high sensitivity, and is harmless to the health. It is a practicable non-contact detection technology for breathing and heartbeat of human body.

Non-mutans streptococci in patients receiving radiotherapy in the head and neck area.

OBJECTIVE: To study mutans and non-mutans streptococci in patients after radiotherapy of the head and neck. METHODS: Oral rinse samples collected from nasopharyngeal carcinoma patients before and after radiotherapy were diluted and cultured on nonselective and selective media for enumeration of total cultivable plaque flora, mutans and non-mutans streptococci and lactobacilli. Non-mutans streptococci were identified biochemically and by 16S rDNA sequence homology analysis. RESULTS: After irradiation, mutans streptococci were not isolated; the levels of Streptococcus mitis and lactobacilli increased significantly. The level of Streptococcus salivarius increased, but the significance was the borderline. The level of Streptococcus sanguis decreased significantly after irradiation. The abundance of other oral streptococci species showed no significant changes. CONCLUSIONS: S. mitis and S. salivarius are the predominant non-mutans streptococci in the high-caries-risk oral flora following radiotherapy.

Degradation of galactomannan by a Clostridium butyricum strain.

An anaerobic, sporeforming, galactomannan-degrading bacterium was isolated from methanogenic granular sludge of an UASB reactor used for treatment of wastewater from a sugar refinery. The isolate degraded the polymer rapidly (doubling time was 55 min) and completely in mineral media. The bacterium was classified as Clostridium butyricum; the main products were acetate, butyrate, hydrogen, formate, and presumably CO2. The strain produced extracellular endo-mannanase, cell-associated exo-mannanase and intracellular alpha-galactosidase activity. The mannanases were present when grown on galactomannan, but not after growth on glucose, galactose, or mannose.

Population distributions of allele frequency of apolipoprotein E by age and gender in Han Chinese.

AIM: To study apolipoproteins E (ApoE) allele frequency in Han Chinese based on age and gender from Shanghai metropolitan area. METHODS: Healthy Han Chinese people (F: 237 and M: 412) were involved in this study. ApoE gene was amplified by PCR using the forward primer: 5'-GGC ACG GCT GTC CAA GGA GCT-3' and reverse primer: 5'-GAT GGC GCT GAG GCC GCG CT-3'. The PCR product was digested directly with 5 units of CfoI and separated by a 20% polyacrylamide nondenaturing gel. RESULTS: ApoE*3 was the commonest allele which accounted for 86.4% of the isoforms, and ApoE*2 and ApoE*4 accounted for 6.2% and 7.5%, respectively. The allele and genotype frequencies were in Hardy-Weinberg equilibrium by comparison with that of the corresponding theoretical distribution (P > 0.05). CONCLUSION: The frequencies of ApoE*2, ApoE*3, and ApoE*4 were demonstrated in the normal Chinese population.

The preparation and characterization of an antimicrobial polypeptide from the loach, Misgurnus anguillicaudatus.

Using Sephadex G-50 gel filtration, DEAE-52 cellulose ion-exchange chromatography, and an improved polyacrylamide gel electrophoresis together with electroelution, a novel polypeptide with antimicrobial activity in vitro was isolated and characterized from loach, Misgurnus anguillicaudatus. The polypeptide, named MAPP, contains about 94 residues containing l0 different amino acids, of which cysteine was the most abundant. No alkaline residue was found in MAPP. MAPP is a single-chain polypeptide with Mw of about 9800Da and pI of about 4.78; the N-terminus of MAPP was CFGWN. MAPP showed good inhibition of various bacteria including Bacillus subtilis, Escherichia coli, and Staphylococcus aureus. MAPP is thermally stable with more than 70% inhibitory bioactivity remaining after treatment at 60 degrees C for 30min. In addition, MAPP could inhibit the autoxidation of pyrogallol with a high efficiency. Similarity searches by comparing amino acid composition, MS-fingerprint, and the N-terminus of MAPP demonstrated that no protein exactly matched MAPP in databases around the world.