Terahertz 3-D fast line-scanning imaging using 3-D printed devices.

This article presents a terahertz (THz) fast line-scanning imaging system with three-dimensional (3-D) focus-steering capability operating at 0.1 THz. The system comprises a 3-D printed rotating multi-prism plate and a dual-device structure consisting of a negative ridge pyramid and a column ridge pyramid. The simulation and experimental results demonstrate that the system generates a sheet-shaped diffraction-free beam with a projection distance of approximately 175 mm and a diffraction-free distance of approximately 200 mm. Moreover, the system maintains a resolution greater than 4 mm within the diffraction-free range. Furthermore, the proposed THz lens-less line-scanning imaging system enables 3-D scanning imaging within a set range of ±22°. The proposed approach can be extended to cover other frequencies within the THz range by appropriately adjusting the parameters. The system has the advantages of long working distance and long depth of field, making it a very attractive candidate for low-cost, easy-fabrication, and easy-adjustment solutions for the next generation of THz fast detection and imaging technology.

Differentiation of parotid pleomorphic adenoma from Warthin tumor using signal intensity ratios on fat-suppressed T2-weighted magnetic resonance imaging.

OBJECTIVE: To investigate the value of magnetic resonance imaging (MRI) signal intensity ratios (SIRs) based on fat-suppressed T2-weighted imaging (FS-T2WI), together with demographic features, MRI anatomical characteristics, and SIRs of histopathological patterns of the tumors, in the differentiation of parotid pleomorphic adenoma (PA) from Warthin tumor (WT). STUDY DESIGN: In total, 90 patients with PA and 56 patients with WT were enrolled in the study. SIRs of tumor to normal parotid gland (SIR-T/P), spinal cord (SIR-T/S), and muscle (SIR-T/M) were calculated. Demographic and radiological features of the 2-patient groups were compared with univariate analysis and multivariate logistic regression analysis. The area under the receiver operating characteristic curve (AUC), sensitivity, and specificity were analyzed to evaluate the utility of SIRs in distinguishing between PA and WT. RESULTS: SIR-T/P exhibited outstanding discriminating ability (AUC = 0.934), SIR-T/S had excellent discrimination (AUC = 0.839), and SIR-T/M showed acceptable discrimination (AUC = 0.728). When SIR-T/P of 1.96 was selected as the cutoff value, sensitivity and specificity were 0.756 and 0.982, respectively. SIR-T/P, age, sex, and number of lesions were identified as independent predictors by multivariate logistic regression analysis. Differences in SIRs between histopathological patterns were significant. CONCLUSION: SIR-T/P based on FS-T2WI is an effective discriminator in the differential diagnosis between PA and WT. Age, sex, and number of lesions provided additional value in differentiation.

Persistent Targeting DNA Nanocarrier Made of 3D Structural Unit Assembled from Only One Basic Multi-Palindromic Oligonucleotide for Precise Gene Cancer Therapy.

Construction of a simple, reconfigurable, and stimuli-responsive DNA nanocarrier remains a technical challenge. In this contribution, by designing three palindromic fragments, a simplest four-sticky end-contained 3D structural unit (PS-unit) made of two same DNA components is proposed. Via regulating the rotation angle of central longitudinal axis of PS-unit, the oriented assembly of one-component spherical architecture is accomplished with high efficiency. Introduction of an aptamer and sticky tail warehouse into one component creates a size-change-reversible targeted siRNA delivery nanovehicle. Volume swelling of 20 nm allows one carrier to load 1987 siPLK1s. Once entering cancer cells and responding to glutathione (GSH) stimuli, siPLK1s are almost 100% released and original size of nanovehicle is restored, inhibiting the expression of PLK1 protein and substantially suppressing tumor growth (superior to commercial transfection agents) in tumor-bearing mice without systemic toxicity.

Magnetic field modulation effect of photoelectric properties in dye-sensitized solar cells with La0.67(Ca,Ba)0.33MnO3 as counter electrodes.

BACKGROUND: In recent years, many semiconductor materials with unique band structures have been used as Pt counter electrode (CE) substitutes for dye-sensitized solar cells (DSSCs), which makes the photoelectric properties of DSSCs possible to be modulated by electric field, magnetic field, and light field. In this work, La0.67(Ca Ba)0.33MnO3 (LCBMO) thin film is employed to act as CE in DSSCs. METHOD: The experimental results indicate that short-circuit current density and photoelectric conversion efficiency present better stability when applying an external magnetic field to the DSSCs. Furthermore, both the exchange current density (J0) and limit diffusion current density (Jlim) are largely enhanced by an external magnetic field. J0 increases from -0.51 mA•cm-2 to -0.65 mA•cm-2, and Jlim increases from 0.2 mA•cm-2 to 0.3 mA•cm-2 when applying a magnetic field of 0.25 T. RESULT: The fitting results of the impedance test verify that the magnetic field reduces the value of Rct. CONCLUSION: Both magnetic-field enhancing catalytic activity and CMR effect jointly promote the increase of photocurrent and finally improve the photovoltaic effect in DSSCs.

Impact of intense physical activity in athletes on intestinal mucosal integrity and its role in acute gastric hemorrhage and postoperative infection risks

In the context of rising gastric disease prevalence, acute gastric hemorrhage presents a significant clinical challenge, particularly among athletes who engage in intense physical activity. This demographic may have unique vulnerabilities due to the stress and strain of their rigorous training and performance routines. Acute gastric bleeding can arise from various sources, including gastritis from Helicobacter pylori infection, gastric ulcers, or vascular abnormalities exacerbated by lifestyle factors like excessive alcohol consumption. However, the impact of high-intensity physical exertion, common in athletes, on these conditions remains underexplored. In athletes, the management of acute gastric bleeding often involves conservative drug therapy post-hemodilation, with proton pump inhibitors like omeprazole offering both anti-inflammatory and acid-inhibiting effects. Surgical intervention is reserved for severe cases, considering the heightened risk of postoperative abdominal infections due to the stomach's unique physiology and its microbial population. This study focuses on the intestinal mucosal barrier's function postoperatively in athletes who have undergone treatment for acute gastric bleeding. We explore how intense physical activity influences intestinal mucosal integrity and its subsequent role in postoperative infection risks. The role of high-mobility group box1 (HMGB1) and the receptor for advanced glycation end products (RAGE) in this context is also examined. HMGB1, a crucial pro-inflammatory cytokine and late inflammatory mediator, and RAGE, a significant HMGB1 receptor, are believed to play pivotal roles in the inflammatory response following acute gastric bleeding (AU)

A facile method for rejuvenating the bonding efficacy of root canal sealer-smeared dentine.

OBJECTIVES: To examine the efficacy of glycine powder air-polishing on cleaning root canal sealer-smeared dentine. METHODS: Dentine surfaces were contaminated with a smear of epoxy resin-based sealer or tricalcium silicate-based sealer. The contaminated surfaces were cleaned with saline, 75% ethanol, or air-polishing with glycine powder. Uncontaminated dentine was used as the control. The cleanliness of pulpal floor dentine was examined using scanning electron microscopy and energy dispersive X-ray analysis. The effectiveness of the three cleaning protocols was examined by testing the tensile bond strength of a self-etching adhesive to the decontaminated dentine. Resin infiltration into the dentinal tubules was identified using confocal laser scanning microscopy (CLSM). RESULTS: Morphological examination and elemental analysis indicated that glycine powder air-polishing was more effective in removing the two sealers. Tensile bond strength of adhesive-bonded dentine was significantly reduced when either sealer was cleaned with saline or ethanol. Conversely, air-polishing restored the adhesive strength of the sealer-smeared dentine to the level of the control. Longer and denser resin tags were identified with CLSM when sealers were removed with air-polishing. CONCLUSIONS: Air-polishing with glycine powder was effective in cleaning sealer-smeared dentine, as demonstrated by the rejuvenation of the tensile bond strength of a self-etching adhesive to the decontaminated dentine. CLINICAL SIGNIFICANCE: Glycine powder air-polishing improves the cleanliness of root canal sealer-smeared dentine and rejuvenates adhesive bonding effectiveness.

Amine organocatalysts for highly ortho-selective chlorination of anilines with sulfuryl chloride.

A metal catalyst free approach for regioselective ortho-chlorination of anilines has been developed using a secondary amine as the organocatalyst and sulfuryl chloride as the halogen source under mild conditions. A wide range of substrates were compatible with this catalytic system. In addition, this catalytic protocol has been applied to the efficient synthesis of bioactive compounds and modification of drug derivatives. Further studies indicated that the anionic trichloride species was responsible for the ortho-selectivity.

NMDAR and JNK Activation in the Spinal Trigeminal Nucleus Caudalis Contributes to Masseter Hyperalgesia Induced by Stress.

It is commonly accepted that psychological stress is closely associated with the occurrence and development of chronic orofacial pain. However, the pathogenesis underlying this process has not been fully elucidated. In the present study, we explored the role of N-methyl-D-aspartate receptors (NMDARs) and Jun N-terminal kinase (JNK) mediated intercellular communication between neurons and astrocytes in the spinal trigeminal nucleus caudalis (Vc) in the induction of masseter hyperalgesia by psychological stress in rats. We found that subjecting rats to 14 days of restraint stress (8 h/d) caused a significant decrease in body weight gain, behavioral changes and marked masseter hyperalgesia in the rats. We also found that exposure to restraint stress for 14 days caused the expression of pJNK in astrocytes in the Vc to significantly increase, and intrathecally infusing a JNK inhibitor significantly prevented restraint stress-induced masseter hyperalgesia in the rats. In addition, after exposure to restraint stress for 14 days, the stressed group exhibited a noticeably increased expression level of pNR2B in neurons in the Vc. Then, we intrathecally injected MK-801 (an NMDAR inhibitor) and ifenprodil (a selective NR2B subunit antagonist) and observed that the two types of inhibitors not only alleviated masseter hyperalgesia but also significantly inhibited the phosphorylation of JNK in the Vc after restraint stress; this indicates that the effect of NMDAR antagonists may influence the activation of astrocytic JNK. Furthermore, inhibitors of neuronal nitric oxide synthase (nNOS) activation and guanylate cyclase (GC) inhibitor could not only inhibit the expression of pJNK in the Vc, but also effectively alleviate masseter hyperalgesia induced by restraint stress. Taken together, our results suggest that NMDAR activation could increase JNK phosphorylation in astrocytes after restraint stress, which may depend on the nNOS-GC pathway. The intercellular communication between neurons and astrocytes in the Vc may play a key role in the induction of masseter muscle hyperalgesia by psychological stress in rats.

The Features of Genetic Prion Diseases Based on Chinese Surveillance Program.

OBJECTIVE: To identify the features of Chinese genetic prion diseases. METHODS: Suspected Creutzfeldt-Jakob disease (CJD) cases that were reported under CJD surveillance were diagnosed and subtyped using the diagnostic criteria issued by the WHO. The general information concerning the patient, their clinical, MRI and EEG data, and the results of CSF 14-3-3 and PRNP sequencing were carefully collected from the database of the national CJD surveillance program and analyzed using the SPSS 11.5 statistical software program. RESULTS: Since 2006, 69 patients were diagnosed with genetic prion diseases and as having 15 different mutations. The median age of the 69 patients at disease onset was 53.5 years, varying from 19 to 80 years. The majority of patients displaying clinical symptoms were in the 50-59 years of age. FFI, T188K gCJD and E200K were the three most common subtypes. The disease appeared in the family histories of 43.48% of the patients. The clinical manifestations varied considerably among the various diseases. Patients who carried mutations in the N-terminus displayed a younger age of onset, were CSF 14-3-3 negative, had a family history of the condition, and experienced a longer duration of the condition. The clinical courses of T188K were significantly shorter than those of FFI and E200K gCJD, while the symptoms in the FFI group appeared at a younger age and for a longer duration. Moreover, the time intervals between the initial neurologist visit to the final diagnosis were similar among patients with FFI, T188K gCJD, E200K gCJD and other diseases. CONCLUSION: The features of Chinese genetic prion diseases are different from those seen in Europe and other Asian countries.

[Sero-epidemiological survey on general community population to understand the infection status after the first wave of pandemic 2009 H1N1 influenza in Guangdong province].

OBJECTIVE: To understand the infection status of pandemic 2009 H1N1 influenza after the first epidemic wave and to estimate the infected population. METHODS: Multi-stage stratified random sampling was introduced with 4500 subjects chosen in Guangdong province. 1500 people were selected from 5 districts (3 streets were selected in every district) in Guangzhou city which was representing the large cities. 1500 people were respectively selected from medium-sized city and rural areas, including 20 cities (1 county or district was selected in every city, at least 1 street or town was selected in every county or district respectively and then 1 - 2 residential area or county was selected in every street or township, respectively). Every sample was selected in accordance with the principle of random sampling, excluding those who had injected with novel H1N1 vaccine. We used hemagglutination inhibition test to understand the serum antibody level of novel H1N1, with title of 1:40 as positive. RESULTS: A number of 4319 specimens, distributed in 21 cities, 25 counties, 85 streets or townships, 144 residential areas, were tested, with an overall positive rate as 22.82% (985/4319). The positive rate of those who had no symptoms of cold since June was 23.47% (471/2007). The positive rate of those who had fever, cough or sore throat was 26.25% (714/2720). The positive rate of those who had influenza-like illness (ILI) was 29.69% (337/1135). CONCLUSION: The infection rate in the first epidemic wave of the novel influenza A (H1N1) pandemic in Guangdong province was 22.82% (985/4317). Based on the number of residents in Guangdong province, the number of natural was estimated to have reached 21.78 million.

Palladium-catalyzed sequential one-pot reaction of aryl bromides with O-homoallylhydroxylamines: synthesis of N-aryl-beta-amino alcohols.

The palladium-catalyzed sequential one-pot N-arylation-carbo-amination-C-arylation of O-homoallylhydroxylamines with two different aryl bromides provides rapid entry to differentially arylated N-aryl-3-arylmethylisoxazolidines in good yields with excellent diastereoselectivity. The obtained isoxazolidines can be reductively cleaved to cis-N-aryl-beta-amino alcohols in short times and in high yields at room temperature.

Preparation of a 7-arylthieno[3,2-d]pyrimidin-4-amine library.

A focused kinase library of 7-arylthieno[3,2-d]pyrimidin-4-amine analogues is readily prepared via solution-phase parallel synthesis. This strategy relies on a key cyclization of a 3-aminothiophene-2-carboxamide with a formamide to construct the thienopyrimidine core. Further elaborations of this core via substitution and Suzuki coupling reactions allow the introduction of other diversity points. This methodology is demonstrated through the preparation of a 72-membered library of 7-arylthieno[3,2-d]pyrimidin-4-amines in good yields and high purities.

Palladium-catalyzed highly stereoselective synthesis of N-aryl-3-arylmethylisoxazolidines via tandem arylation of O-homoallylhydroxylamines.

The palladium-catalyzed tandem arylation of O-homoallylhydroxylamines with 2 equiv of aryl bromides was examined. With Pd2(dba)3 (1 mol %) as the catalyst, Xantphos (2 mol %) as the ligand, and NaOt-Bu as the base, the reactions of O-homoallylhydroxylamines with aryl bromides via sequential N-arylation/cyclization/C-arylation in toluene afforded the corresponding N-aryl-3-arylmethylisoxazolidines in good yields with excellent diastereoselectivity.

[Successful preimplantation genetic diagnosis for alpha-thalassemia using fluorescent polymerase chain reaction].

OBJECTIVE: To develop single-cell fluorescent gap polymerase chain reaction (PCR) assay for preimplantation genetic diagnosis (PGD) in couples at risk of having child with alpha-thalassemia. METHODS: Single cell fluorescent gap PCR which can detect the alpha-thalassemia Southeast Asia deletion (-SEA deletion), was applied to single lymphocytes and blastomeres which coming from four clinical PGD cycles. RESULTS: The Single cell fluorescent gap PCR can detect the alpha-thalassemia -SEA deletion, which account for 94% of hydrop fetalis in Chinese population with an amplification efficiency of 90.0% (72/80) and allele drop-out (ADO) rate of 8.3% (6/72) in lymphocytes. In four clinical PGD cycles, a total 38 embryos were detected and 38 blastomeres were obtained. Thirty-four blastomeres were amplified with the amplification efficiency of 89.5% (34/38) and ADO rate of 5.9% (2/34). Eleven embryos were shown to be normal homozygous, eight embryos were shown to be heterozygous and 15 embryos were shown to be affected homozygous. Eleven embryos were transferred back to the uterus of the patients. Two pregnancy achieved, resulting in two live healthy births, which confirmed the results of PGD. CONCLUSION: This first reported unaffected pregnancy resulting from PGD using fluorescent gap PCR for alpha-thalassemia demonstrates that this technique, as an alternative to prenatal diagnosis, is a reliable and effective way to help those carrier couples to get a healthy baby.

7-substituted 8-aza-7-deazapurines and 2,8-diaza-7-deaza-purines: synthesis of nucleosides and oligonucleotides.

7-Substituted 8-aza- 7-deazaadenosines 1a-e were synthesized by Sonogashira cross coupling from the corresponding 7-iodo nucleoside in 36-79% yields. Starting from 7-bromo (or 7-iodo)-8-aza-7-deazaadenine, 2a,b were obtained by acid-catalyzed glycosylation followed by deprotection in 53 and 35% yields, repectively. Compounds 2b was applied to cross coupling reaction to give 2c-d in 34-95% yield. Compounds 2a and 4b were further transformed to the phosphoramidites 5 and 6b in 9 and 49% overall yields, which were incorporated into oligonucleotides.

8-Aza-7-deaza-7-propynyladenosine methanol solvate.

In the title compound, 4-amino-3-propynyl-1-(beta-D-ribofuranosyl)-1H-pyrazolo[3,4-d]pyrimidine methanol solvate, C13H15N5O4.CH3OH, the torsion angle of the N-glycosylic bond is between anti and high-anti [chi = -101.8 (5) degrees ]. The ribofuranose moiety adopts the C3'-endo (3T2) sugar conformation (N-type) and the conformation at the exocyclic C-C bond is +sc (gauche, gauche). The propynyl group is out of the plane of the nucleobase and is bent. The compound forms a three-dimensional network which is stabilized by several hydrogen bonds (O-H...O and O-H...N). The nucleobases are stacked head-to-tail. The methanol solvent molecule forms hydrogen bonds with both the nucleobase and the sugar moiety.

1,N6-Etheno-7-deaza-2,8-diazaadenosine: syntheses, properties and conversion to 7-deaza-2,8-diazaadenosine.

1,N6-Etheno-7-deaza-2,8-diazaadenosine (4) was synthesized from 8-aza-7-deazaadenosine (6) in 64% overall yield. The starting material 6 was obtained by the direct glycosylation of 8-aza-7-deazaadenine (7) with 1-O-acetyl-2,3,5-tri-O-benzoyl-beta-d-ribofuranose (8) (NO2 CH3, BF3 x Et2O; 77% yield). Compound 4 was transformed into 7-deaza-2,8-diazaadenosine (5). The fluorescence of compound 4 shows an emission maximum at 531 nm (phosphate buffer; pH 7.0), which is bathochromically shifted compared to 1,N(6)-etheno-2-azaadenosine (3a) (495 nm). A conformational analysis was performed in the solid state and in solution.