[Observation on the efficacy of different targets low-frequency repetitive transcranial magnetic stimulation for the treatment of tremor-dominant subtypes of Parkinson's disease]

Objective: To analyze the efficacy of different targets low-frequency repetitive transcranial magnetic stimulation (rTMS) for the treatment of tremor Parkinson's disease(PD). Method: A total of 82 patients with primary PD who were admitted to the Department of Neurology, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from April 1, 2020 to March 31, 2021 were prospectively collected. According to the clinical characteristics of major movement disorders, 82 patients with tremor type (TD) were selected to enroll.The patients were randomly divided into 3 groups at a 1∶1∶1 ratio according to the randomized coding sequence of the trial: the primary motor cortex (M1) group with 26 cases, the cerebellum group with 26 cases and the dual-site (M1, cerebellum) group with 30 cases. All patients were treated with 1 Hz low-frequency stimulation of the corresponding target once a day for 5 days a week for 2 weeks, a total of 10 times; The dosage remained unchanged during the treatment for all groups. Before and after 2 weeks' treatment, the patients were assessed with the Unified PD Rating Scale (UPDRS) and PD Quality of Life Questionnaire-39 (PDQ-39) without medication. Cortical excitability, namely transcranial magnetic stimulation motor evoked potential (TMS-MEP), [including resting motor threshold (rMT) and active motor threshold (aMT) examinations], timed up and go (TUG) and electromyographic tremor were conducted. Result: There were 82 patients, 39 males and 43 females, with an average age of (67±8) years. Before the treatment, there was no statistically significant difference in the evaluation indicators among the three groups (all P>0.05). After the treatment, the differences of the UPDRS-Ⅲ score [(38.9±2.5) vs (29.2±3.6) ], UPDRS tremor score [(23.7±2.1) vs (14.6±3.1) ], TUG time [(44.8±3.1) s vs (33.7±4.1) s], tremor amplitude [(480±126) μV vs (276±94) μV], PDQ-39 score [(51±13) vs (45±13) ], rMT [(36±17)% vs (43±13)%], and aMT [(26±16)% vs (31±12)%] were statistically significant (all P<0.01) from those before the treatment. There was no statistical difference in the above factors between the M1 group and cerebellum group (all P>0.05). There was no statistically significant difference in tremor peak frequency among the three groups before and after the treatment (all P>0.05). Conclusions: Dual-site low-frequency rTMS can improve PD tremor, while M1 or cerebellar low-frequency rTMS does not significantly improve PD tremor. Its mechanism may be to improve PD tremor symptoms by regulating cortical excitability.

Measurement of oesophageal hiatus surface area by multiplanar reconstruction of MDCT: relationship with lower oesophageal sphincter pressure and acid reflux

AIM

To evaluate the relationship between oesophageal hiatus surface area (OHSA) and gastro-oesophageal reflux disease (GERD).

MATERIALS AND METHODS

Patients who underwent 24-h pH monitoring, oesophageal high-resolution manometry, and upper abdominal contrast-enhanced multidetector computed tomography (MDCT) during 2014-2021 were enrolled. Patients with a hiatus hernia (HH) on MDCT or who had a history of gastro-oesophageal surgery were excluded. Multiplanar reconstruction (MPR) of the MDCT image was used for the measurement of OHSA. Correlations of OHSA with acid exposure time (AET) and lower oesophageal sphincter (LOS) pressure of all patients were analysed.

RESULTS

Seventy-eight patients were included in the study. OHSA was much less in the AET <4% group than in the AET >6% group (1.61 ± 0.42 versus 2.09 ± 0.55 cm2, p<0.001). Correlation analysis reveals that OHSA correlated positively with AET (correlation coefficient = 0.47, p<0.001). Receiver operating characteristic (ROC) curve analysis reveals that OHSA can significantly distinguish patients in different groups divided by AET (area under the ROC curve [AUC] = 0.76, 95% confidence interval [CI]: 0.63-0.90). OHSA was not related to LOS pressure (correlation coefficient = -0.268, p=0.051). There was no difference in OHSA between the low LOS pressure group and the normal LOS pressure group (1.84 ± 0.61 versus 1.74 ± 0.50 cm2, p=0.52).

CONCLUSIONS

OHSA significantly correlated with AET but has no relationship with LOS pressure. It may be an independent risk factor of GERD.

Observation of a Strongly Isospin-Mixed Doublet in ^{26}Si via β-Delayed Two-Proton Decay of ^{26}P

β decay of proton-rich nuclei plays an important role in exploring isospin mixing. The β decay of ^{26}P at the proton drip line is studied using double-sided silicon strip detectors operating in conjunction with high-purity germanium detectors. The T=2 isobaric analog state (IAS) at 13 055 keV and two new high-lying states at 13 380 and 11 912 keV in ^{26}Si are unambiguously identified through β-delayed two-proton emission (β2p). Angular correlations of two protons emitted from ^{26}Si excited states populated by ^{26}P β decay are measured, which suggests that the two protons are emitted mainly sequentially. We report the first observation of a strongly isospin-mixed doublet that deexcites mainly via two-proton decay. The isospin mixing matrix element between the ^{26}Si IAS and the nearby 13 380-keV state is determined to be 130(21) keV, and this result represents the strongest mixing, highest excitation energy, and largest level spacing of a doublet ever observed in β-decay experiments.

[The clinical efficacy of the stratification medical treatment based on the risk estimation of motor complications in Parkinson's disease]

Objectives: To evaluate the clinical efficacy of the stratification medical treatment based on the motor complications risk estimation in improving the quality of life, motor symptoms and delaying the motor complications in Parkinson's patients. Methods: Outpatients and inpatients from Xinhua Hospital, Shanghai Jiao Tong University, were recruited between November 2019 and June 2020. The participants were all clinically diagnosed with PD and treated with anti-PD medications, but had no history of motor complications, with the 8-item Parkinson's disease questionnaire summary index (PDQ-8 SI)>18.59. At baseline, the demographic characteristics, PD medical history, levodopa dosage (LD) and levodopa equivalent dosage (LED) were collected, and the evaluation of PDQ-8, Unified Parkinson's disease rating scale (UPDRS)-Ⅱ and Ⅲ, Hoehn and Yahr (H&Y) grade, Hamilton anxiety scale-14 (HAMA-14), Hamilton depression scale-24 (HAMD-24), mini-mental state examination (MMSE), Pittsburgh sleep quality index (PSQI), and Epworth sleepiness scale (ESS) tools was accomplished in all participants. Meanwhile, a Parkinson's disease risk estimation scale for motor complications was used to assess patients' risk of motor complications, and thus the medication was stratified in PD patients accordingly. During the 6-month and 12-month follow-ups, the evaluation of the above-mentioned parameters was repeated in all participants. At the 3-month and 9-month follow-ups, the information of anti-PD medications, the occurrence of motor complications (motor fluctuations and dyskinesia) and adverse drug reactions were recorded, and PDQ-8 was also evaluated. Results: Two hundred and fifty-one patients completed the 1-year follow-up, with 135 males and 116 females. At baseline, the median age of the patients was 66 (60, 71) years and the median PDQ-8 SI was 31.2 (21.9, 40.6). Additionally, 15.9% (40/251) of the patients were at high risk of motor fluctuation, and 7.2% (18/251) were at high risk of dyskinesia. There were significant differences in the age of onset, disease duration, PD treatment duration, the scores of UPDRS-Ⅱ and Ⅲ, H&Y Grade, and PDQ-8 SI among PD patients of different risk groups (all P<0.05). In the 12th month, the median of PDQ-8 SI, Δ PDQ-8 SI and Δ UPDRS-Ⅲ was 12.5 (9.4, 18.8), -15.6 (-21.9, -9.4) and -9(-16, -4), respectively, which was statistically different from that of baseline (all P<0.05). The change of UPDRS-Ⅱ scores in the group with high risk of motor fluctuation was statistically different from that in the groups with low and moderate risk (P<0.05). The changes of PSQI score, LD and LED in the group with high risk of dyskinesia was statistically different from those in the groups with low and moderate risk (all P<0.05). During the follow-up, the incidence of motor fluctuation and dyskinesia was 9.56% (24/251) and 5.97% (15/251), respectively. Conclusion: The stratification medical treatment might have a positive intervention effect on promoting a better quality of life, improving motor symptoms and delaying motor complications in PD patients.

16S rRNA gene amplicon sequencing of gut microbiota in gestational diabetes mellitus and their correlation with disease risk factors

PURPOSE

Although the gut microbiota (GM) are associated with various diseases, their role in gestational diabetes mellitus (GDM) remains uncharacterized. Further study is urgently needed to expose the real relationship between GM and GDM.

METHODS

We performed a prospective study in 33 pregnant Chinese individuals [15, GDM; 18, normal glucose tolerance (NGT)] to observe the fecal microbiota by 16S rRNA gene amplicon sequencing at 24-28 weeks of gestational age after a standard 75 g oral glucose tolerance test. Linear regression analysis was employed to assess the relationships between the GM and GDM clinical parameters.

RESULTS

Sequencing showed no difference in the microbiota alpha diversity but a significant difference in the beta diversity between the GDM and NGT groups, with the relative abundances of Ruminococcus bromii, Clostridium colinum, and Streptococcus infantis being higher in the GDM group (P < 0.05). The quantitative PCR results validated the putative bacterial markers of R. bromii and S. infantis. Moreover, a strong positive correlation was found between S. infantis and blood glucose levels after adjusting for body mass index (P < 0.05).

CONCLUSION

Three abnormally expressed intestinal bacteria (R. bromii, C. colinum, and S. infantis) were identified in GDM patients. S. infantis may confer an increased risk of GDM. Hence, the GM may serve as a potential therapeutic target for GDM.

[Investigation on high-frequency hearing loss of noise workers in an automobile factory]

Objective: To investigate the high-frequency hearing loss (HFHL) of workers in an automobile factory and its influencing factors, so as to provide a scientific basis for occupational health management of noise workers. Methods: From March to July 2019, 2647 workers from an automobile factory were selected as the research objects by cluster sampling method. The basic personal information (such as gender, age, education level, height, weight, etc.) , history of ear disease, the history of detonation, history of exposure to ototoxic drugs, history of exposure to occupational noise, etc., were investigated by questionnaire and occupational health examination. Chi-square test was used to compare the detection rates of HFHL in different populations, and multivariate logistic regression model was used to analyze the influencing factors of HFHL. Results: The noise level of 2647 individual workers ranged from 75.0 dB (A) to 92.0 dB (A) , with an average of (84.14±2.47) dB (A) . The detection rate of HFHL was 17.2% (456/2647) . There were significant differences in the the detection rate of HFHL among workers of different gender, age, educational level, working age, noise exposure level, diabetes history, detonation history, smoking and drinking workers (P<0.05) . Multivariate logistic regression analysis showed that male, age ≥30 years old, smoking and noise exposure were risk factors for HFHL (P<0.05) . Conclusion: The detection rate of HFHL in automobile factory workers is high. Gender, age, smoking and noise are the influencing factors of HFHL. It is necessary to strengthen the noise control in the workplace and guide workers to choose healthy lifestyle.

New α-Emitting Isotope ^{214}U and Abnormal Enhancement of α-Particle Clustering in Lightest Uranium Isotopes

A new α-emitting isotope ^{214}U, produced by the fusion-evaporation reaction ^{182}W(^{36}Ar,4n)^{214}U, was identified by employing the gas-filled recoil separator SHANS and the recoil-α correlation technique. More precise α-decay properties of even-even nuclei ^{216,218}U were also measured in the reactions of ^{40}Ar, ^{40}Ca beams with ^{180,182,184}W targets. By combining the experimental data, improved α-decay reduced widths δ^{2} for the even-even Po-Pu nuclei in the vicinity of the magic neutron number N=126 are deduced. Their systematic trends are discussed in terms of the N_{p}N_{n} scheme in order to study the influence of proton-neutron interaction on α decay in this region of nuclei. It is strikingly found that the reduced widths of ^{214,216}U are significantly enhanced by a factor of two as compared with the N_{p}N_{n} systematics for the 84≤Z≤90 and N<126 even-even nuclei. The abnormal enhancement is interpreted by the strong monopole interaction between the valence protons and neutrons occupying the π1f_{7/2} and ν1f_{5/2} spin-orbit partner orbits, which is supported by the large-scale shell model calculation.

New ^{59}Fe Stellar Decay Rate with Implications for the ^{60}Fe Radioactivity in Massive Stars

The discrepancy between observations from γ-ray astronomy of the ^{60}Fe/^{26}Al γ-ray flux ratio and recent calculations is an unresolved puzzle in nuclear astrophysics. The stellar β-decay rate of ^{59}Fe is one of the major nuclear uncertainties impeding us from a precise prediction. The important Gamow-Teller strengths from the low-lying states in ^{59}Fe to the ^{59}Co ground state are measured for the first time using the exclusive measurement of the ^{59}Co(t,^{3}He+γ)^{59}Fe charge-exchange reaction. The new stellar decay rate of ^{59}Fe is a factor of 3.5±1.1 larger than the currently adopted rate at T=1.2  GK. Stellar evolution calculations show that the ^{60}Fe production yield of an 18 solar mass star is decreased significantly by 40% when using the new rate. Our result eliminates one of the major nuclear uncertainties in the predicted yield of ^{60}Fe and alleviates the existing discrepancy of the ^{60}Fe/^{26}Al ratio.

A Prospective Study of Diffusion-weighted Magnetic Resonance Imaging as an Early Prognostic Biomarker in Chemoradiotherapy in Squamous Cell Carcinomas of the Anus

AIMS

The use of diffusion-weighted magnetic resonance imaging (DW-MRI) as a prognostic marker of treatment response would enable early individualisation of treatment. We aimed to quantify the changes in mean apparent diffusion coefficient (ΔADC_mean) between a DW-MRI at diagnosis and on fraction 8-10 of chemoradiotherapy (CRT) as a biomarker for cellularity, and correlate these with anal squamous cell carcinoma recurrence.

MATERIALS AND METHODS

This prospective study recruited patients with localised anal cancer between October 2014 and November 2017. DW-MRI was carried out at diagnosis and after fraction 8-10 of radical CRT. A region of interest was delineated for all primary tumours and any lymph nodes >2 cm on high-resolution T₂-weighted images and propagated to the ADC map. Routine clinical follow-up was collected from Nation Health Service electronic systems.

RESULTS

Twenty-three of 29 recruited patients underwent paired DW-MRI scans. Twenty-six regions of interest were delineated among the 23 evaluable patients. The median (range) tumour volume was 13.6 cm³ (2.8-84.9 cm³). Ten of 23 patients had lesions with ΔADC_mean ≤ 20%. With a median follow-up of 41.2 months, four patients either failed to have a complete response to CRT or subsequently relapsed. Three of four patients with disease relapse had lesions demonstrating ΔADC_mean <20%, the other patient with persistent disease had ΔADC_mean of 20.3%.

CONCLUSIONS

We demonstrated a potential correlation between patients with ΔADC_mean <20% and disease relapse. Further investigation of the prognostic merit of DW-MRI change is needed in larger, prospective cohorts.

Determinants of SARS-CoV-2 receptor gene expression in upper and lower airways

The recent outbreak of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has led to a worldwide pandemic. One week after initial symptoms develop, a subset of patients progresses to severe disease, with high mortality and limited treatment options. To design novel interventions aimed at preventing spread of the virus and reducing progression to severe disease, detailed knowledge of the cell types and regulating factors driving cellular entry is urgently needed. Here we assess the expression patterns in genes required for COVID-19 entry into cells and replication, and their regulation by genetic, epigenetic and environmental factors, throughout the respiratory tract using samples collected from the upper (nasal) and lower airways (bronchi). Matched samples from the upper and lower airways show a clear increased expression of these genes in the nose compared to the bronchi and parenchyma. Cellular deconvolution indicates a clear association of these genes with the proportion of secretory epithelial cells. Smoking status was found to increase the majority of COVID-19 related genes including ACE2 and TMPRSS2 but only in the lower airways, which was associated with a significant increase in the predicted proportion of goblet cells in bronchial samples of current smokers. Both acute and second hand smoke were found to increase ACE2 expression in the bronchus. Inhaled corticosteroids decrease ACE2 expression in the lower airways. No significant effect of genetics on ACE2 expression was observed, but a strong association of DNA- methylation with ACE2 and TMPRSS2- mRNA expression was identified in the bronchus.

Epidemiological characteristics and spatial-temporal analysis of COVID-19 in Shandong Province, China

The pandemic of coronavirus disease 2019 (COVID-19) has posed serious challenges. It is vitally important to further clarify the epidemiological characteristics of the COVID-19 outbreak for future study and prevention and control measures. Epidemiological characteristics and spatial-temporal analysis were performed based on COVID-19 cases from 21 January 2020 to 1 March 2020 in Shandong Province, and close contacts were traced to construct transmission chains. A total of 758 laboratory-confirmed cases were reported in Shandong. The sex ratio was 1.27: 1 (M: F) and the median age was 42 (interquartile range: 32-55). The high-risk clusters were identified in the central, eastern and southern regions of Shandong from 25 January 2020 to 10 February 2020. We rebuilt 54 transmission chains involving 209 cases, of which 52.2% were family clusters, and three widespread infection chains were elaborated, occurring in Jining, Zaozhuang and Liaocheng, respectively. The geographical and temporal disparity may alert public health agencies to implement specific measures in regions with different risk, and should attach importance on how to avoid household and community transmission.

The conjugation of targeted therapy and image-guided phototdynamic therapy of cancer in vitro and in vivo

Integration of multi-functional diagnosis and treatment competencies can improve effect of the drug and its visual distribution to the location of tumor focus site, and play a pivotal role by visualizing the tumor size in the assessment of chemotherapy. With the objective of developing integrated multi-therapeutic and diagnostic agent that could target the kinase receptor with high expression in tumor cells, herein, a biologically releasable drug-drug conjugate compound 9 with dual therapeutic and diagnostic effects was designed, synthesized and evaluated for pharmacodynamics and diagnostic functions in vitro and in vivo. The results of antitumor effects evaluations and compound 9 visual imaging indicated that compound 9 not only improved the anti-proliferative activity of chemotherapy and photodynamic treatment (PDT) in vitro and in vivo compared with those of compound 8 and PpIX but also allowed the photodynamic diagnosis (PDD). The present study verified a facile and effective strategy using a drug-drug conjugate to integrate diagnosis and multi-therapies, showing its potential a candidate clinical drug.

Isospin Properties of Nuclear Pair Correlations from the Level Structure of the Self-Conjugate Nucleus ^{88}Ru

The low-lying energy spectrum of the extremely neutron-deficient self-conjugate (N=Z) nuclide _{44}^{88}Ru_{44} has been measured using the combination of the Advanced Gamma Tracking Array (AGATA) spectrometer, the NEDA and Neutron Wall neutron detector arrays, and the DIAMANT charged particle detector array. Excited states in ^{88}Ru were populated via the ^{54}Fe(^{36}Ar,2nγ)^{88}Ru^{*} fusion-evaporation reaction at the Grand Accélérateur National d'Ions Lourds (GANIL) accelerator complex. The observed γ-ray cascade is assigned to ^{88}Ru using clean prompt γ-γ-2-neutron coincidences in anticoincidence with the detection of charged particles, confirming and extending the previously assigned sequence of low-lying excited states. It is consistent with a moderately deformed rotating system exhibiting a band crossing at a rotational frequency that is significantly higher than standard theoretical predictions with isovector pairing, as well as observations in neighboring N>Z nuclides. The direct observation of such a "delayed" rotational alignment in a deformed N=Z nucleus is in agreement with theoretical predictions related to the presence of strong isoscalar neutron-proton pair correlations.

[The first identification of epidemic clone of enterotoxic Escherichia coli O∶6 serogroup highly associated with azithromycin resistance in Shanghai]

Objective: To investigate the molecular characterization of adult diarrhea cases caused by enterotoxic Escherichia coli (ETEC) and explore the practical model of epidemiology for laboratory technique and data needs based on the surveillance network. Methods: Epidemiological design and sampling targeted adult cases ETEC caused diarrhea in epidemic season. The enterotoxin type, serogroup, resistance, colonization factor and molecular type of ETEC were identified. Multiple dynamic phenotypic characteristics of ETEC were indicated by multidimensional and multivariable data. Results: From 2016 to 2018, 84 eligible ETEC strains were detected. The dominant serums/toxins were O∶6 (STh), O∶25 (LT), O∶159 (STh), O∶153 (STh). O∶6 (STh+CS21), which replaced O∶25 and O∶159 as the popular clones in 2018. Six cases of O∶153 (STh+CFA/I+CS8+PT34) in outbreak in 2017 were imported ones. The resistance rates of ETEC strains detected in adults to sulfasoxazole, naproxinic acid, ampicillin and azithromycin were more than 30%, multidrug resistance (MDR) reached 58.3%. Serum/toxin types suggested that attenuated strains were more likely to become MDR. Molecular typing confirmed that the genetic similarity of the dominant clone of O∶6 serogroup (PT20-24) was higher than O∶25 and O∶159. There was a high correlation between the minimal inhibitory concentration (MIC) of azithromycin and the resistant gene mphA (87.5%, 28/32). O∶6 (STh+CS21+mphA) resistant clone was first detected in 2016. Conclusion: A new epidemic clone in adult ETEC diarrhea cases in Shanghai was O∶6 (STh+CS21+mphA). For the first time the association between azithromycin resistance gene mphA and a serum group of ETEC was observed. Multidimensional and multivariate analysis techniques based on epidemiology can help reveal the potential transmission pattern of ETEC for the accurate surveillance and early warning of outbreaks.

Expression of miR-33 from an SREBP2 intron inhibits the expression of the fatty acid oxidation-regulatory genes CROT and HADHB in chicken liver

1. Limiting the growth of adipose tissue in chickens is a major issue in the poultry industry. In chickens, de novo synthesis of lipids occurs primarily in the liver. Thus, it is necessary to understand how fatty acid accumulation in the liver is controlled. The miR-33 is an intronic microRNA (miRNA) of the chicken sterol regulatory element binding transcription factor 2 (SREBF2), which is a master switch in activating many genes involved in the uptake and synthesis of cholesterol, triglycerides, fatty acids and phospholipids. 2. In the current study, the genes CROT and HADHB known to encode enzymes critical for fatty acid oxidation were predicted to be potential targets of miR-33 in chickens via the miRNA target prediction programs 'miRanda' and 'TargetScan'. Co-transfection and dual-luciferase reporter assays showed that the expression of luciferase reporter gene linked to the 3'-untranslated region (3'UTR) of the chicken CROT and HADHB mRNA was down-regulated by overexpression of the chicken miR-33 (P < 0.05). This down-regulation was completely abolished when the predicted miR-33 target sites in the CROT and HADHB 3'UTR were mutated. 3. Transfecting miR-33 mimics into the LMH cells led to a decrease in the mRNA expression of CROT and HADHB (P < 0.01), and this transfection had a similar effect on the proteins (P < 0.05). In contrast, the expression of CROT in primary chicken hepatocytes was up-regulated after transfection with the miR-33 inhibitor LNA-anti-miR-33 (P < 0.05). 4. Using quantitative RT-PCR, it was shown that the expression of miR-33 was increased in the chicken liver from day 0 to day 49 of age, whereas the CROT and HADHB mRNA levels decreased during the same period. 5. These findings support the conclusion that miR-33 might play an important role in lipid metabolism in the chicken liver by negatively regulating the expression of the CROT and HADHB genes, which encode enzymes critical for lipid oxidation.

Cloning and identification of mouse steroid receptor coactivator-1 (mSRC-1), as a coactivator of peroxisome proliferator-activated receptor gamma

Peroxisome proliferator-activated receptor gamma (PPARgamma), a member of the nuclear receptor superfamily, is expressed predominantly in adipose tissue. Forced expression of the two isoforms of this receptor, PPARgamma1 and PPARgamma2, in fibroblasts initiates a transcriptional cascade that leads to the development of adipocyte phenotype. Using the yeast two-hybrid system and GAL4-PPARgamma as bait to screen mouse liver cDNA library, we isolated a mouse steroid receptor coactivator (mSRC-1) involved in nuclear hormone receptor transcriptional activity as a mPPARgamma interactive protein. mSRC-1 cDNA we isolated contains an open reading frame of 1447 amino acids and encodes a new member of the basic helix-loop-helix-PAS domain family. We show that the binding of mSRC-1 to mPPARgamma is ligand independent and coexpression of mSRC-1 with mPPARgamma increases the transcriptional activity of mPPARgamma in the presence of mPPARgamma ligand. We have identified the presence of two putative mPPARgamma binding sites in the mSRC-1, one between residues 620 and 789, and the second between residues 1231 and 1447. These two regions exhibit different degrees of binding affinity for mPPARgamma. We also show that mSRC-1 exhibits its own constitutive transcriptional activity in the yeast as well as in mammalian cells. These results suggest that mSRC-1 interacts with PPARgamma and plays a role in the PPARgamma-mediated signaling pathway.

Lifetime Measurements of Excited States in ^{172}Pt and the Variation of Quadrupole Transition Strength with Angular Momentum

Lifetimes of the first excited 2^{+} and 4^{+} states in the extremely neutron-deficient nuclide ^{172}Pt have been measured for the first time using the recoil-distance Doppler shift and recoil-decay tagging techniques. An unusually low value of the ratio B(E2:4_{1}^{+}→2_{1}^{+})/B(E2:2_{1}^{+}→0_{gs}^{+})=0.55(19) was found, similar to a handful of other such anomalous cases observed in the entire Segré chart. The observation adds to a cluster of a few extremely neutron-deficient nuclides of the heavy transition metals with neutron numbers N≈90-94 featuring the effect. No theoretical model calculations reported to date have been able to explain the anomalously low B(E2:4_{1}^{+}→2_{1}^{+})/B(E2:2_{1}^{+}→0_{gs}^{+}) ratios observed in these cases. Such low values cannot, e.g., be explained within the framework of the geometrical collective model or by algebraic approaches within the interacting boson model framework. It is proposed that the group of B(E2:4_{1}^{+}→2_{1}^{+})/B(E2:2_{1}^{+}→0_{gs}^{+}) ratios in the extremely neutron-deficient even-even W, Os, and Pt nuclei around neutron numbers N≈90-94 reveal a quantum phase transition from a seniority-conserving structure to a collective regime as a function of neutron number. Although a system governed by seniority symmetry is the only theoretical framework for which such an effect may naturally occur, the phenomenon is highly unexpected for these nuclei that are not situated near closed shells.

Synthesis and evaluation of novel 18 F-labeled quinazoline derivatives with low lipophilicity for tumor PET imaging

Four novel ¹⁸ F-labeled quinazoline derivatives with low lipophilicity, [¹⁸ F]4-(2-fluoroethoxy)-6,7-dimethoxyquinazoline ([¹⁸ F]I), [¹⁸ F]4-(3-((4-(2-fluoroethoxy)-7-methoxyquinazolin-6-yl)oxy)propyl)morpholine ([¹⁸ F]II), [¹⁸ F]4-(2-fluoroethoxy)-7-methoxy-6-(2-methoxyethoxy)quinazoline ([¹⁸ F]III), and [¹⁸ F]4-(2-fluoroethoxy)-6,7-bis(2-methoxyethoxy)quinazoline ([¹⁸ F]IV), were synthesized via a 2-step radiosynthesis procedure with an overall radiochemical yield of 10% to 38% (without decay correction) and radiochemical purities of >98%. The lipophilicity and stability of labeled compounds were tested in vitro. The log P values of the 4 radiotracers ranged from 0.52 to 1.07. We then performed ELISA to measure their affinities to EGFR-TK; ELISA assay results indicated that each inhibitor was specifically bounded to EGFR-TK in a dose-dependent manner. The EGFR-TK autophosphorylation IC₅₀ values of [¹⁸ F]I, [¹⁸ F]II, [¹⁸ F]III, and [¹⁸ F]IV were 7.732, 0.4698, 0.1174, and 0.1176 μM, respectively. All labeled compounds were evaluated via cellular uptake and blocking studies in HepG2 cell lines in vitro. Cellular uptake and blocking experiment results indicated that [¹⁸ F]I and [¹⁸ F]III had excellent cellular uptake at 120-minute postinjection in HepG2 carcinoma cells (51.80 ± 3.42%ID/mg protein and 27.31 ± 1.94%ID/mg protein, respectively). Additionally, biodistribution experiments in S180 tumor-bearing mice in vivo indicated that [¹⁸ F]I had a very fast clearance in blood and a relatively high uptake ratio of tumor to blood (4.76) and tumor to muscle (1.82) at 60-minute postinjection. [¹⁸ F]III had a quick clearance in plasma, and its highest uptake ratio of tumor to muscle was 2.55 at 15-minute postinjection. These experimental results and experiences were valuable for the further exploration of novel radiotracers of quinazoline derivatives.

Direct Measurement of Single-Molecule Adenosine Triphosphatase Hydrolysis Dynamics

F₁-ATPase (F₁) is a bidirectional molecular motor that hydrolyzes nearly all ATPs to fuel the cellular processes. Optical observation of labeled F₁ rotation against the α₃β₃ hexamer ring revealed the sequential mechanical rotation steps corresponding to ATP binding/ADP release and ATP hydrolysis/Pi release. These substeps originate from the F₁ rotation but with heavy load on the γ shaft due to fluorescent labeling and the photophysical limitation of an optical microscope, which hampers better understanding of the intrinsic kinetic behavior of ATP hydrolysis. In this work, we present a method capable of electrically monitoring ATP hydrolysis of a single label-free F₁ in real time by using a high-gain silicon nanowire-based field-effect transistor circuit. We reproducibly observe the regular current signal fluctuations with two distinct levels, which are induced by the binding dwell and the catalytic dwell, respectively, in both concentration- and temperature-dependent experiments. In comparison with labeled F₁, the hydrolysis rate of nonlabeled F₁ used in this study is 1 order of magnitude faster (1.69 × 10⁸ M^-1 s^-1 at 20 °C), and the differences between two sequential catalytic rates are clearer, demonstrating the ability of nanowire nanocircuits to directly probe the intrinsic dynamic processes of the biological activities with single-molecule/single-event sensitivity. This approach is complementary to traditional optical methods, offering endless opportunities to unravel molecular mechanisms of a variety of dynamic biosystems under realistic physiological conditions.

Regional specificity of matrix metalloproteinase-9 expression in the brain: voxel-level mapping in primary glioblastomas

AIM

To investigate the anatomical specificity of matrix metalloproteinase-9 (MMP-9) expression in glioblastomas by using voxel-based neuroimaging analysis.

MATERIALS AND METHODS

Clinical information and preoperative magnetic resonance images of 133 patients with glioblastomas were reviewed. Evaluation of MMP-9 expression was performed by using immunohistochemistry. Tumour lesions were segmented manually basing on the structural image of each patient, then registered to a standard brain atlas. Voxel-based regression analysis was subsequently performed to identify the specific brain regions that were associated with MMP-9 expression levels.

RESULTS

A significantly larger lesion volume of T2-hyperintensity was demonstrated in tumours with low MMP-9 expression compared to those with high MMP-9 expression (p=0.010). No significant difference was found in the lesion volumes of the contrast enhancement areas between the two groups (p=0.452). The major correlated cluster with high MMP-9 expression was identified in the right frontal lobe, while a cluster located at the posterior region of the right lateral ventricle was correlated with low MMP-9 expression.

CONCLUSION

Voxel-based statistical analysis revealed the anatomical specificity of MMP-9 expression levels in glioblastoma. The identified correlation between molecular biomarkers and anatomical distribution may increase our understanding of the biological characteristics of glioblastoma and provide new insight into the molecular subtypes of glioblastoma.

Single Nucleotide Polymorphism Genotyping in Single-Molecule Electronic Circuits

Establishing low-cost, high-throughput, simple, and accurate single nucleotide polymorphism (SNP) genotyping techniques is beneficial for understanding the intrinsic relationship between individual genetic variations and their biological functions on a genomic scale. Here, a straightforward and reliable single-molecule approach is demonstrated for precise SNP authentication by directly measuring the fluctuations in electrical signals in an electronic circuit, which is fabricated from a high-gain field-effect silicon nanowire decorated with a single hairpin DNA, in the presence of different target DNAs. By simply comparing the proportion difference of a probe-target duplex structure throughout the process, this study implements allele-specific and accurate SNP detection. These results are supported by the statistical analyses of different dynamic parameters such as the mean lifetime and the unwinding probability of the duplex conformation. In comparison with conventional polymerase chain reaction and optical methods, this convenient and label-free method is complementary to existing optical methods and also shows several advantages, such as simple operation and no requirement for fluorescent labeling, thus promising a futuristic route toward the next-generation genotyping technique.

Hypoxia stimulates neural stem cell proliferation by increasing HIF‑1α expression and activating Wnt/β-catenin signaling

Evidence indicates that after brain injury, neurogenesis is enhanced in regions such as hippocampus, striatum, and cortex. To study the role of hypoxia-inducible factor-1 (HIF‑1α) and Wnt signaling in cerebral ischemia/hypoxia-induced proliferation of neural stem cells (NSCs), we investigated the proliferation of NSCs, expression of HIF‑1α, and activation of Wnt signaling under conditions of pathologic hypoxia in vitro. NSCs were isolated from 30-day-old Sprague-Dawley rats and subjected to 0.3% oxygen in a microaerophilic incubation system. Cell proliferation was evaluated by measuring the diameter of neurospheres and by bromodeoxyuridine incorporation assays. Real-time quantitative PCR and Western blotting were used to detect mRNA and protein levels of HIF-1α, β-catenin, and cyclin D1 in the NSCs. The results showed that hypoxia increased NSC proliferation and the levels of HIF-1α, β‑catenin, and cyclin D1 (p &lt; 0.05). Blockade of the Wnt signaling pathway decreased hypoxia-induced NSC proliferation, whereas activation of this pathway increased hypoxia-induced NSC proliferation (p &lt; 0.05). Knockdown of HIF-1α with HIF-1α siRNA decreased β‑catenin nuclear translocation and cyclin D1 expression, and inhibited proliferation of NSCs (p &lt; 0.05). These findings indicate that pathologic hypoxia stimulates NSC proliferation by increasing expression of HIF-1α and activating the Wnt/β-catenin signaling pathway. The data suggest that Wnt/β-catenin signaling may play a key role in NSC proliferation under conditions of pathologic hypoxia.

Development of a series of novel 4-anlinoquinazoline derivatives possessing quinazoline skeleton: Design, synthesis, EGFR kinase inhibitory efficacy, and evaluation of anticancer activities in vitro

4-anilinoquinazoline-based derivatives represent an attractive scaffold for small molecular EGFR-TKIs in the field of medicinal chemistry. A series of novel heterocyclic substituted derivatives have been designed, synthesized and evaluated their antitumor bioactivities as potential EGFR-TKIs. Most of the new compounds exhibited certain efficient inhibition potency for proliferation of a panel of five human cancer cells with IC₅₀ values at the low micromolar level, and some of them possessed good broad-spectrum inhibition activities, compared to Gefitinib. Especially, the IC₅₀ values of compound 21 against HepG2, A549, MCF-7, DU145 and SH-SY5Y cells were 4.61, 9.50, 9.80, 6.79 and 7.77 μM, respectively, which were much lower than those of Gefitinb. Furthermore, the highlighting compound 21 demonstrated excellent inhibition activity against EGFR-TK with the IC₅₀ value of 3.62 nM, similar to that of Gefitinib(2.21 nM). The results of LDH release assay proved that compound 21 was anti-proliferative rather than cytotoxicity on HepG2 cells. Compound 21 were able to cause HepG2 cells to block in S phase and induce cell death mainly by apoptosis through a mitochondrial dependent pathway. Moreover, the assessment of MMP, the determination of intracellular free Ca²⁺ concentration, the production of ROS, and the effects on the activity of caspase-3 in a dose-dependent manner demonstrated that compound 21 induced cell apoptosis in HepG2 cells through the Ca²⁺/ROS-mediated mitochondria/caspase-dependent apoptosis pathway largely. These preliminary results evidenced that compound 21 could be a potential antitumor agent deserving further study.

Direct real-time detection of single proteins using silicon nanowire-based electrical circuits

We present an efficient strategy through surface functionalization to build a single silicon nanowire field-effect transistor-based biosensor that is capable of directly detecting protein adsorption/desorption at the single-event level. The step-wise signals in real-time detection of His-tag F₁-ATPases demonstrate a promising electrical biosensing approach with single-molecule sensitivity, thus opening up new opportunities for studying single-molecule biophysics in broad biological systems.

Design and synthesis of novel pyrazolo[1,5-a]pyrimidine derivatives bearing nitrogen mustard moiety and evaluation of their antitumor activity in vitro and in vivo

A series of novel pyrazolo[1,5-a]pyrimidine derivatives bearing nitrogen mustard moiety were designed, synthesized and evaluated for their antiproliferative activities against five human cancer cell lines (A549, SH-SY5Y, HepG2, MCF-7 and DU145) in vitro. Among these compounds, 13b exhibited potent inhibitory effect on the proliferation of the five tumor cells and was able to inhibit cell cycle arrest at G1 phase and induce cell apoptosis. In HepG2 HCC xenograft compound 13b was selected for evaluating the antitumor activity in vivo which exhibited significant cancer growth inhibition with low host toxicity in vivo.

[Measurement and analysis of hand-transmitted vibration of vibration tools in workplace for automobile casting and assembly]

OBJECTIVE

To investigate the features of hand-transmitted vibration of common vibration tools in the workplace for automobile casting and assembly.

METHODS

From September to October, 2014, measurement and spectral analysis were performed for 16 typical hand tools(including percussion drill, pneumatic wrench, grinding machine, internal grinder, and arc welding machine) in 6 workplaces for automobile casting and assembly according to ISO 5349-1-2001 Mechanical vibration-Measurement and evaluation of human exposure to hand-transmitted vibration-part 1: General requirements and ISO 5349-2-2001 Mechanical vibration-Measurement and evaluation of human exposure to hand-transmitted vibration-Part 2: Practical guidance for measurement in the workplace.

RESULTS

The vibration acceleration waveforms of shearing machine, arc welding machine, and pneumatic wrench were mainly impact wave and random wave, while those of internal grinder, angle grinder, percussion drill, and grinding machine were mainly long-and short-period waves. The daily exposure duration to vibration of electric wrench, pneumatic wrench, shearing machine, percussion drill, and internal grinder was about 150 minutes, while that of plasma cutting machine, angle grinder, grinding machine, bench grinder, and arc welding machine was about 400 minutes. The range of vibration total value(ahv) was as follows: pneumatic wrench 0.30~11.04 m/s(2), grinding wheel 1.61~8.97 m/s(2), internal grinder 1.46~8.70 m/s(2), percussion drill 11.10~14.50 m/s(2), and arc welding machine 0.21~2.18 m/s(2). The workers engaged in cleaning had the longest daily exposure duration to vibration, and the effective value of 8-hour energy-equivalent frequency-weighted acceleration for them[A(8)] was 8.03 m/s(2), while this value for workers engaged in assembly was 4.78 m/s(2). The frequency spectrogram with an 1/3-time frequency interval showed that grinding machine, angle grinder, and percussion drill had a high vibration acceleration, and the vibration limit curve was recommended for those with a frequency higher than 400 min/d.

CONCLUSION

The workers who are engaged in cleaning, grinding, and a few positions of assembly and use grinding machine, angle grinder, internal grinder, and percussion drill are exposed to vibrations with a high vibration acceleration and at a high position of the frequency spectrum. The hand-transmitted vibration in the positions of cutting, polishing, and cleaning in automobile casting has great harm, and the harm caused by pneumatic wrench in automobile assembly should be taken seriously.