A simple and sensitive method was developed for the detection of mercury ions with quartz crystal microbalance(QCM), based on the specific thymine(T)-Hg2+-T structure and gold nanoparticles. The gold nanoparticles were prepared by the citrate reduction method. In a self-assembled way, the particle surface was modified with the probe oligonucleotides which were partially replaced by 6-Mercaptohexan-1-ol to reduce the steric hindrance of hybridization. The sensitivity was optimized by the oligonucleotide with a strand length of 9bp and a T number of 7. The linear range was 5.0-100 nmol/L with a detection limit of 2.0 nmol/L. And Ca2+, Mg2+ and other metal ions had no significant interferences. This method was successfully applied for the detection of Hg2+in environmental water samples, with RSD less than 2.9% and recoveries of 97.3%-101.2%.

Aptamers are oligo-nucleotides which are selected by SELEX (systematic evolution of ligands by exponential enrichment) in vitro, it can bind protein or other small molecules with high specificity and affinity. Researches on aptamers have achieved much progress in biosensor, drug development and nano technology. This article has reviewed the researches and applications of aptamers in the past two years.
Animals ; Aptamers, Nucleotide ; isolation & purification ; Biosensing Techniques ; methods ; Drug Design ; Humans ; Nanotechnology ; methods ; SELEX Aptamer Technique

A method combinating piezoelectric-biochip technique with cell culture technique in vitro has been developed. Piezoelectric cell-based chip (PCC) can continously monitor the behaviors of living cells attached to or spreaded on surfaces. The method measures the resonant frequency (f), the dissipation energy (D) and impedance (Z), in real time. These multi parameters can inflect information of cells qualitively and quantitively. This paper covers principle, materials and methods, results and discussion of the new technique, simultaniously indicates its application and trends.
Cytological Techniques ; instrumentation ; methods ; Electric Impedance ; Electrodes ; In Vitro Techniques ; Time Factors

Testicular aging is mainly characterized by a gradual decline in the capability of testosterone synthesis and spermatogenesis, which not only affects male fertility, but also correlates with aging-related chronic diseases intimately. Therefore, delaying testicular aging plays a significant role in improving the health and quality of life of middle-aged and elderly men. Stem cells are a cell group with potent self-renewal capability and multi-directional differentiation potential. In recent years, the research of stem cells in basic and clinical application has been carried out in-depth, which has accelerated the development of cell therapy. Currently, stem cell transplantation has been employed to treat multiple diseases, which has captivated widespread attention in the field of aging and regenerative medicine. Stem cell transplantation has demonstrated promising prospects in the treatment of testicular aging. In this article, research profile and progress of stem cell transplantation in the treatment of testicular aging were reviewed, and bottleneck issues encountered in clinical translation and strategies for optimizing clinical efficacy were discussed, aiming to provide novel ideas for the research and development and clinical translation of stem cell therapy for testicular aging.

Objective:To evaluate whether there are changes in cone cells in patients with pre-clinical hydroxychloroquine (HCQ) retinopathy using an adaptive optics (AO) retinal camera.Methods:A retrospective case-control study. From May 2020 to July 2020, 46 patients who were treated in Department of Rheumatism and Immunology, Hainan Hospital of PLA General Hospital with rheumatic immune diseases were included. All patients had a history of HCQ use and no obvious abnormality was found in fundus examination; 105 healthy people with similar demographic characteristics without a history of hydroxychloroquine were recruited as the control group were included. All subjects received the routine ophthalmological examination including best corrected visual auity (BCVA), spectral-domain optical coherence tomography (SD-OCT), Fundus autofluorescence (FAF), visual field, endoscopy of the cornea, and the measurement of axial length (AL). The BCVA was performed with the Snellen visual acuity chart, and the result was converted to logarithmic minimum angle of resolution (logMAR) visual acuity for statistic. Among the 46 cases, 6 cases were males and 40 cases were females. Age was (42.02±13.81) years old; logMAR BCVA was 0.063±0.015; AL was (23.95±0.726) mm. Visual field, macular SD-OCT, FAF examination showed no abnormality. The average cumulative dose of HCQ was 522.60 (6-1 728) g. rtx1 AO retinal camera was used to collect fundus images of subjects in four quadrants above the retina, nasal side, lower side and temporal side with 3°centrifugation from the fovea in both eyes. The cone density, cone spacing, cone arrangement regularity and the proportion of the nearest cones with 6 (nn=6) were measured in the four quadrants. The density of cone cells between the left and right eyes in case group and control group were compared by paired t test. The density and spacing of cone cells in each quadrant were compared by t test of two independent samples. Results:Compared with the control group, the cone cell density in the four quadrants of the left eye and the nasal, superior and inferior sides of the right eye in the case group was significantly decreased, and the difference was statistically significant ( t=4.247, 2.107, 4.884, 2.254, 2.643, 4.445, 4.116; P<0.05). The cone spacing in the nasal and temporal sides of the left eye of the patients in the case group was significantly larger than that in the control eye, with statistical significance ( t=2.750, 3.318; P<0.05). Compared with the control group, the regulatign of cone cell arrangement in the left temporal side of the right and left eye in the case group were significantly reduced, the difference was statistically significant ( P=0.002, 0.011). The proportion of nn=6 in the inferior and temporal sides of the right eye decreased significantly in the case group, and the difference was statistically significant ( P=0.006, 0.032). Conclusion:AO retinal imaging can detect the changes of cone cells in the early clinical stage of HCQ retinopathy.

Objective: To analyze the clinical value of real-time PCR for virus detection in the diagnosis and treatment of patients after allo-HSCT who had no infection evidence of pneumonia using routine pathogen detection panel. Methods: The clinical data of 71 episodes with acute lung injury from May 2015 to March 2017 after allo-HSCT in hematology department of Peking University People’s Hospital (PKUPH) were retrospectively analyzed. PCR for virus detection and other routine pathogen detection tests were performed on bronchoalveolar lavage fluid (BALF) samples. Results: Among 71 episodes with acute lung injury, a total of 15 patients were diagnosed as lower respiratory tract disease merely associated with virus (detection rate of 21.13%) , 19 episodes were absent of lower respiratory tract infection. The median time from allo-HSCT to the occurrence of lung injury were 176 (49-1 376) d and 196 (57-457) d respectively (z=-0.191, P=0.864) . There were no statistical differences for baseline characteristics and clinical features between two groups. The 100-day attributable mortalities were 13.3% (2/15) and 26.3% (5/19) (χ²=0.864, P=0.426) . Patients with low-dose steroids treatment had favorable outcome than those with high-dose steroids treatment (the dose of methylprednisolone ≥250 mg/d as standard) [4.2% (1/24) vs 60.0% (6/10) ]. In patients with detectable virus in BALF, 2 patients died with early high-dose steroids treatment, while 11 patients survived with no steroids treatment or late application. Conclusions Virus infection should be considered in post-HSCT pneumonia patient with negative result using routine pathogen detection panel. Expanding virus detection panel by PCR in BALF could increase diagnostic precision and might be instructive to treatment.

Hepatitis B virus ; drug effects ; physiology ; Hodgkin Disease ; drug therapy ; Humans ; Immunoconjugates ; therapeutic use ; Virus Activation ; drug effects