Content measurement of doxorubicin hydrochloride and lonidamine by HPLC / 药学实践与服务

Objective To establish a method for the simultaneous determination of DOX·HCl and LND. Methods HPLC was performed on Agilent 5 HC-C18（2） （4.6 mm × 250 mm, 5 µm） column. The mobile phase was methanol-0.1% TFA aqueous solution, and the gradient elution procedure were: 0 to 3 min, 65% methanol; 3 to 7 min, 65%→90% methanol; 7 to 13 min, 90% methanol; 13 to 15 min, 90%→65% methanol; 15 to 20 min, 65% methanol. The collection time was 20 min, the balance time was 3 min, the UV detection wavelengths were 205 nm and 253 nm. The flow rate was 1.0 ml/min and the column temperature was 35℃. The amount of inlet was 10 µl. Results The method was highly specific, and both DOX·HCl and LND exhibited good linearity in the concentration range of 1-40 µg/ml and 6-240 µg/ml, respectively. The two compounds’ precision, stability, and recovery satisfied the requirements of the method. Conclusion This study established a HPLC method that was suitable for the simultaneous detection of DOX·HCl and LND. This method’s high level of specificity, accuracy, and reliability .

Three-dimensional magnetization prepared rapid acquisition gradient echo for evaluation on the corpus callosum morphological alterations in children with spastic cerebral palsy / 实用放射学杂志

Objective To analyze the morphological alterations of corpus callosum in children with spastic cerebral palsy(SCP)using three-dimensional magnetization prepared rapid acquisition gradient echo(3D-MPRAGE)technology and to investigate the correlation between morphological indexes and gross motor function.Methods Sagittal T1WI 3D-MPRAGE data was collected from 136 children with SCP(SCP group)and 132 age-and gender-matched healthy controls(HC)(HC group),and the gross motor function measure-88(GMFM-88)was applied to assess the gross motor function.Independent sample t-test was used to compare the corpus callosum surface area,volume,maximum anterior-posterior diameter,median sagittal area(total area and area of Ⅰ-Ⅴ zone)between the two groups.Partial correlation analysis was performed to calculate the correlation between morphological indexes of the corpus callosum and GMFM-88 with age as a covariate.Results Children under 3 years old,the corpus callosum surface area of the SCP group(3 914.51 mm2±1 207.97 mm2)was lower than that of the HC group(5 725.51 mm2±1 412.66 mm2).The volume of the corpus callosum(6 108.46 mm3±2 803.97 mm3)in the SCP group was lower than that of the HC group(11 297.96 mm3±4 109.02 mm3).Also,the maximum anterior-posterior diameter of the corpus callosum in the SCP group(53.40 mm±6.31 mm)was lower than that of the HC group(57.74 mm±6.04 mm)(all P<0.05).Children over 3 years old,the corpus callosum surface area of the SCP group(4 970.06 mm2±1 191.31 mm2)was lower than that of the HC group(6 372.55 mm2±1 445.59 mm2).The volume of the corpus callosum(8 330.20 mm3±2 888.20 mm3)in the SCP group was lower than that of the HC group(13 599.82 mm3±3 429.81 mm3)(all P<0.05).Partial correlation analysis showed significant correlation between corpus callosum volume,median sagittal area and gross motor score(P<0.01)with age as a covari-ate.Conclusion The 3D-MPRAGE technology can be useful for the comprehensive assessment of morphological alterations of the corpus callosum in SCP.The corpus callosum volume,and median sagittal area may become neuroimaging references for the assess-ment of motor development in cerebral palsy(CP).

Structural design and mechanical property analysis of trabecular scaffold of triply periodic minimal surface with a radial gradient / 中国组织工程研究

BACKGROUND:The elastic modulus of traditional bone implants is large and does not match the elastic modulus of human bone,which will cause a stress shielding effect and lead to bone resorption.The trabecular scaffold of the triply periodic minimal surface with radial gradient has elastic modulus matching with human cancellous bone,and its yield strength is greater than that of human cortical bone,which provides a new choice for the design of bone scaffold. OBJECTIVE:Triply periodic minimal surface structure with radial gradient was constructed by the implicit surface method.The sample was manufactured by laser selective melting technology,and the quasi-static compression test was carried out to obtain trabecular scaffolds with mechanical properties matching human bones. METHODS:Four types of the trabecular scaffolds of the triply periodic minimal surface with a radial gradient of G,I,P and D were established by the implicit surface method.Samples were manufactured by laser selective melting technology.We observed the surface morphology of the molded sample,evaluated the molding quality,conducted a quasi-static compression test,and evaluated the mechanical properties of the samples. RESULTS AND CONCLUSION:The quasi-static compression test results showed that compared with the four triply periodic minimal surface scaffolds,the platform stress of the G scaffold had less fluctuation and no failure or fracture,indicating that the G scaffold had the best plasticity.The mechanical properties of the G scaffolds with 45%,55%and 65%porosities were analyzed.It was found that the elastic modulus of G scaffolds with 55%porosity was within the range of elastic modulus of human cancellous bone(0.022-3.7 GPa),and the yield strength was close to the maximum yield strength of human cortical bone(187.7-222.3 MPa).In conclusion,G triply periodic minimal surface scaffold with 55%porosity can reduce the stress shielding effect,bear a higher body load,improve the stability of the implant,and prolong the service life of the implant.

Reshaping the Cortical Connectivity Gradient by Long-Term Cognitive Training During Development / 神经科学通报·英文版

The organization of the brain follows a topological hierarchy that changes dynamically during development. However, it remains unknown whether and how cognitive training administered over multiple years during development can modify this hierarchical topology. By measuring the brain and behavior of school children who had carried out abacus-based mental calculation (AMC) training for five years (starting from 7 years to 12 years old) in pre-training and post-training, we revealed the reshaping effect of long-term AMC intervention during development on the brain hierarchical topology. We observed the development-induced emergence of the default network, AMC training-promoted shifting, and regional changes in cortical gradients. Moreover, the training-induced gradient changes were located in visual and somatomotor areas in association with the visuospatial/motor-imagery strategy. We found that gradient-based features can predict the math ability within groups. Our findings provide novel insights into the dynamic nature of network recruitment impacted by long-term cognitive training during development.

Exploration of Optimizing Density Gradient Centrifugation in Semen Processing to Improve Fertilization Outcomes / 中山大学学报(医学科学版)

ObjectiveThis study aimed to improve the existing semen processing methods in the field of reproductive male medicine， particularly focusing on the 300 ×g 20 min treatment condition in the double-layer density gradient method， to enhance fertilization outcome. MethodsSemen specimens from 1 623 patients undergoing assisted reproductive techniques at the Reproductive Medicine Center of the Sixth Affiliated Hospital of Sun Yat-sen University from July and September 2020 and March and May 2022 were collected for preliminary experiments. Four different double-layer density gradient methods （200 ×g 10 min， 200 ×g 20 min， 300 ×g 10 min， and 300 ×g 20 min） were compared for sperm DNA fragmentation rates and recovery rates after processing. Subsequently， the optimal method was selected as the new approach and compared with the current method in use （300 ×g 20 min double-layer gradient method） to assess any statistical differences in fertilization rates. Further optimization to a single-layer density gradient method was performed based on the new method and compared with the double-layer density gradient method to determine any statistical differences. Experimental conditions were strictly controlled for temperature， centrifugation speed， and duration， with the quantity and processing conditions of each sample recorded. ResultsAmong the four double-layer density gradient methods， the sperm DNA fragmentation rate was lower with the 300 ×g 10 min treatment compared to 300 ×g 20 min while ensuring sufficient sperm recovery rates. Consequently， the 300 ×g 10 min method was selected as the new approach for experimentation. Results indicated that the total fertilization rate and 2 pronuclei （2PN） fertilization rate with the new 300 ×g 10 min method were higher than with the 300 ×g 20 min method， the difference was statistically significant （P < 0.05）. Although the cleavage rate with 300 ×g 10 min was slightly higher than 300 ×g 20 min， the difference was not statistically significant （P > 0.05）. The total fertilization rate and 2PN fertilization rate were slightly higher with the single-layer density gradient method compared to the double-layer density gradient method， but the difference was not statistically significant （P > 0.05）. The cleavage rate with the single-layer density gradient method was higher than the double-layer density gradient method， and the blastocyst formation rate is lower than that of the double-layer density gradient method， and the differences are statistically significant （P < 0.05）. ConclusionThe 300 ×g 10 min double-layer density gradient method successfully improved total fertilization rates， 2PN fertilization rates， and cleavage rates compared to the existing 300 ×g 20 min method， while reducing the time required for semen optimization processing. Although the single-layer density gradient method improves the cleavage rate， and saves reagent costs and operation time， its blastocyst formation rate has decreased. These findings provide valuable guidance and insights for semen processing methods in the field of reproductive andrology.

Research on machine learning-based activity prediction models for KRAS inhibitors / 中国药科大学学报

@#Abstract: Kirsten rat sarcoma viral oncogene homolog (KRAS) gene is one of the most commonly mutated oncogenes. It has been found that KRAS inhibitors have the potential therapeutic effect on cancer patients with this gene mutation. In this study, machine learning was applied to develop a QSAR(quantitative structure-activity relationship) model for KRAS small molecule inhibitors. A total of 1857data points of IC50 and SMILES(simplified molecular input line entry system) for KRAS inhibitors were collected from three databases: ChEMBL, BindingDB, and PubChem. And nine different classifiers were constructed using three different feature screening methods combined with three machine learning models, namely, random forest, support vector machine, and extreme gradient boosting machine. The results showed that the SVM model combined with mutual information feature selection exhibited the best performance: AUCtest=0.912, ACCtest=0.859, F1test=0.890. Moreover, it also demonstrated good predictive performance on the external validation set(AUCExt=0.944, RecallExt=0.856, FPRExt=0.111). This study provides a new technical route for KRAS inhibitor screening in natural product databases using artificial intelligence methods.

Predictive value of infiltrating zone contrast-enhanced ultrasound gradient features in Nottingham grading and pathologically true infiltration of invasive ductal carcinoma / 中华超声影像学杂志

Objective:To investigate the predictive value of infiltrating zone contrast-enhanced ultrasound(CEUS) gradient features in Nottingham grading and pathologically true infiltration of invasive ductal carcinoma(IDC).Methods:A retrospective analysis was performed on 78 female breast cancer patients (95 masses) confirmed by surgical and pathology in the Affiliated Hospital of Jiangsu University from July 2019 to June 2022, which were divided into Grade-Ⅰ (22 masses), Grade-Ⅱ (28 masses), and Grade-Ⅲ (45 masses) according to the Nottingham histological grading system. The differences in the maximum diameter of the infiltration zone and the characteristic parameters of the gradient of the inner and outer edges of the infiltration zone among the three groups of masses were compared, and the differential gradient features among them were analyzed by multivariate ordered Logistic regression and ROC curves. The relationship between the differential gradient characteristics of the infiltration zone and the pathologically true infiltration of the mass was further explored.Results:The univariate analysis showed statistically significant differences among the three groups for peak-arrival time gradient (ΔTTP), ascending branch slope gradient (ΔRS), peak intensity gradient (ΔPI) and area gradient under the curve (ΔAUC) (all P<0.05). Multiple ordered logistic regression analysis showed that ΔTTP, ΔPI and ΔAUC had independent influences on the histologic grading of IDC (all P<0.05), and the area under the curve for the combination of the three in predicting IDC histology grades Ⅰ, Ⅱ and Ⅲ was 0.692, 0.705 and 0.765, respectively. In addition, the maximum diameter of pathologically true infiltration of the mass was positively correlated with ΔTTP ( r=0.621, P<0.05) and negatively correlated with ΔPI ( r=-0.605, P<0.05) and ΔAUC ( r=-0.719, P<0.05). Conclusions:Infiltration zone CEUS gradient features are effective in predicting the histologic grade of IDC and strongly correlate with the degree of pathologically true infiltration of the mass.

Segmentation Clock Networks in Vertebrate Somitogenesis / 生物化学与生物物理进展

In vertebrate embryonic development, the segmentation clock controls the cyclic formation of somites through presomitic mesoderm (PSM) cells. Somites are paired segmented structures along the anterior-posterior axis that eventually develop into vertebrae and ribs. Disruptions in the segmentation clock leads to defects in somitogenesis, resulting in congenital spinal diseases. The major patterning modules that are involved in segmentation clock is the clock and wavefront, which primarily relies on signaling gradients and cyclic oscillation. Mesodermal differentiation is regulated by combinatorial gradient system that involves the activity of the fibroblast growth factor (FGF), the Wnt/β-catenin, and the retinoic acid (RA) signaling pathways. The antagonistic gradients of these signals set a position of the determination front. In the tail bud and posterior mesoderm, FGF and Wnt signaling prevent cell maturation and the molecular oscillators start to express. The molecular oscillators rely on negative feedback loops to maintain their oscillatory expression patterns. As the cells move anteriorly, FGF signaling gradually decays and RA signaling began to strengthen. Meanwhile, the molecular oscillators propagate anteriorly with wave pattern. At the determination front, low levels of FGF signaling and high levels of RA signaling eliminate differentiation inhibition and initiate molecular oscillators to activate cyclic genes, such as Mesp2, leading to the formation of repetitive structures in somites. Advancements in live reporter and 2D culture systems have revealed that coupling delays in cell communication can maintain the synchronous segmentation clock between adjacent cells. Studies have shown that these coupling delays are controlled by Lfng gene, it can adjust coupling delays to fit in-phase oscillations by increasing the time required for intercellular DLL1-Notch signaling. To sum up, the dual homeostasis of opposing signaling gradients determines the segment boundaries, the distance traveled by a molecular oscillator in one oscillation cycle determines the somite size, and the delayed coupling in intercellular signaling regulates the synchronization of clock oscillations. These three factors interact with each other to form a segmentation clock network coordinating somitogenesis. Recent studies have revealed that the intercellular coupling delay mechanism is a major factor influencing the maintenance of oscillation synchronization. Intercellular coupling delay errors, such as increased or decreased delay time, can desynchronizing intercellular oscillations and resulting in somite fusion. However, the mechanisms governing how intercellular communication becomes involved in oscillation synchronization remains unclear. Congenital scoliosis (CS) is a result of anomalous development of the vertebrate which associate with somitogenesis malformation. We observed that deficiency or overdose of vitamin A intake in gestation may lead to CS. While the deep mechanism of how RA signaling regulates oscillation synchronization still need to be detected. With the rapid development of 3D culture systems, researchers have successfully recapitulated the formation of somite-like structures with antero-posterior identity and indicated that the rate of metabolism is directly proportional to that of development. In summary, deconstructing the segmentation clock in vitro facilitates the dissection of regulation networks of the segmentation clock and offers an excellent proxy for studying the metabolic regulation of somitogenesis speed across species and the mechanisms underlying the formation of bilateral symmetry. It also creates a platform for exploring dysregulation mechanisms involved in the development of pathological somite defects.

Neural Representation of Multiple Spatial Scales / 生物化学与生物物理进展

Spatial environment includes multiple scales, which can be specifically divided into operable near-scale figural space, navigable space consisting of single-viewpoint space and environmental space, and large-scale geographic space. It is very important for human and other animal’s daily life to distinguish the spatial environment at different scales. The representation of spatial scale is related to its corresponding functional requirements. The parietal lobe is responsible for the representation of near-scale space. Navigable spatial representation in the hippocampus and cerebral cortex shows a “coarse to fine” gradient along the posterior to anterior axis. However, the scale representation of abstract social space shows a dichotomy. Future research should focus on temporal dynamics of spatial scale representation and the influence of spatial scale on the format of the cognitive map.

Timing of semen cryopreservation: before or after processing?

Abstract Objective: Seminal cryopreservation causes significant damage to the sperm; therefore, different methods of cryopreservation have been studied. The aim of the study was to compare the effects of density gradient processing and washing/centrifugation with seminal plasma removal for cryopreservation in semen parameters. Methods: Seminal samples of 26 normozoospermic patients were divided into 3 parts: with seminal plasma; after washing/centrifugation; and after selection through density gradient. The samples were cryopreserved for at least two weeks. Motility, sperm count, morphology and viability were evaluated before cryopreservation and after thawing. Results: Density gradient processing selected motile and viable sperm with normal morphology in fresh samples (p<0.05). Cryopreservation negatively affected all sperm parameters regardless of the processing performed, and even if the sperm recovery was lower in the density gradient after the thawing, progressive motility, total motility, viability and morphology remained higher (p<0.05). Conclusion: Cryopreservation significantly compromises sperm parameters (motility, morphology, viability). In normozoospermic patients, the density gradients select better quality spermatozoa compared to other processing methods; this benefit was kept after thawing.

Diversidad y estructura del bosque de niebla en la Sierra Madre de Chiapas, México

Introducción: Los bosques de niebla se caracterizan por su distribución insular en sistemas montañosos tropicales. Florísticamente son complejos y heterogéneos, y con vacíos de información que afectan la comprensión de cómo varía su diversidad y estructura. Objetivo: Analizar los patrones de diversidad, estructura y composición del bosque de niebla en México. Métodos: Contamos y medimos plantas leñosas en 40 parcelas de 0.1 ha de cinco sitios en aproximadamente 200 km a lo largo de la Sierra Madre de Chiapas, México (1 700 - 2 100 m.s.n.m.). Usamos tres métodos estadísticos: análisis de varianza (diversidad verdadera y estructura entre sitios), regresión simple y métodos multivariados (clima y elevación). Resultados: Registramos 4 021 individuos (220 especies, 60 familias). En la diversidad verdadera, solo encontramos diferencias en riqueza de especies, con un ligero incremento hacia la parte central del área. La diversidad fue constante para especies comunes y dominantes. No encontramos diferencias en la densidad de árboles o área basal entre los sitios. Sin embargo, hubo menor densidad y mayor área basal a mayores elevaciones. La diversidad beta y la diferenciación en la composición florística es alta e importante entre las parcelas de un mismo sitio y se incrementa con la distancia entre los sitios. Conclusiones: La diversidad beta y la diferenciación florística contribuyen significativamente en la variación del bosque de niebla. Las variables climáticas y la altitud tienen efectos distintos sobre la diversidad y estructura.

Introduction: Cloud forests are noted for their narrow distribution in tropical mountain systems. Floristically, they are complex and heterogeneous, with gaps in information that hinder the understanding of how their diversity and structure vary. Objective: To analyze patterns of diversity, structure, and composition of the cloud forest in Mexico. Methods: We counted and measured woody plants in forty 0.1 ha plots from five sites in approximately 200 km along the Sierra Madre of Chiapas, Mexico (1 700 - 2 100 m.a.s.l.). We used three statistical methods: analysis of variance (diversity true and structure among sites), simple regression and multivariate statistics (climate and elevation). Results: We recorded 4 021 individuals (220 species, 60 families). In true diversity, we only found differences for species richness, with a slight increase toward the central part of the area. Diversity was constant for common and dominant species. We found no differences in tree density or basal area between sites. However, there was less density and more basal area at higher elevations. Beta diversity and differentiation in floristic composition are high and important between plots of the same site, and they increase with distance between sites. Conclusions: Beta diversity and floristic differentiation significantly contribute to variation in the cloud forest. Climatic variables and altitude have different effects on diversity and structure.

Antibacterial effect of low-temperature plasma on Enterococcus faecalis in dentinal tubules in vitro / 北京大学学报(医学版)

OBJECTIVE@#To construct a model of Enterococcus faecalis (E. faecalis) infection in dentinal tubules by gradient centrifugation and to evaluate the antibacterial effect of low-temperature plasma on E. faecalis in dentinal tubules.@*METHODS@#Standard dentin blocks of 4 mm×4 mm×2 mm size were prepared from single root canal isolated teeth without caries, placed in the E. faecalis bacterial solution, centrifuged in gradient and incubated for 24 h to establish the model of dentinal tubule infection with E. faecalis. The twenty dentin blocks of were divided into five groups, low-temperature plasma jet treatment for 0, 5 and 10 min, calcium hydroxide paste sealing for 7 d and 2% chlorhexidine gel sealing for 7 d. Scanning electron microscopy and confocal laser scanning microscope were used to assess the infection in the dentinal tubules and the antibacterial effect of low-temperature plasma.@*RESULTS@#The results of scanning electron microscopy and confocal laser scanning microscopy showed that after 24 h of incubation by gradient centrifugation, E. faecalis could fully enter the dentinal tubules to a depth of more than 600μm indicating that this method was time-saving and efficient and could successfully construct a model of E. faecalis infection in dentinal tubules. Low-temperature plasma could enter the dentinal tubules and play a role, the structure of E. faecalis was still intact after 5 min of low-temperature plasma treatment, with no obvious damage, and after 10 min of low-temperature plasma treatment, the surface morphology of E. faecalis was crumpled and deformed, the cell wall was seriously collapsed, and the normal physiological morphology was damaged indicating that the majority of E. faecalis was killed in the dentinal tubules. The antibacterial effect of low-temperature plasma treatment for 10 min exceeded that of the calcium hydroxide paste sealing for 7 d and the 2% chlorhexidine gel sealing for 7 d. These two chemicals had difficulty entering deep into the dentinal tubules, and therefore only had a few of antibacterial effect on the bacterial biofilm on the root canal wall, and there was also no significant damage to the E. faecalis bacterial structure.@*CONCLUSION@#Gradient centrifugation could establish the model of E. faecalis dentin infection successfully. Low-temperature plasma treatment for 10 min could kill E. faecalis in dentinal tubules effectively, which is superior to the calcium hydroxide paste sealing for 7 d and the 2% chlorhexidine gel sealing for 7 d.

Value of hepatic venous pressure gradient in preoperative evaluation and prognosis prediction in liver transplant recipients / 器官移植

Hepatic venous pressure gradient (HVPG) is the "gold standard" for the diagnosis of portal hypertension, which could be applied in the evaluation of liver cirrhosis. Combined use of HVPG with model for end-stage liver disease (MELD) scoring system may more accurately match the donors and recipients undergoing liver transplantation for liver cirrhosis, select the appropriate timing of surgery, and provide guidance for bridging treatment for patients on the waiting list for liver transplantation. Besides, HVPG may also predict clinical prognosis of liver transplant recipients, and provide evidence for early detection and intervention of potential complications. Therefore, the value of HVPG in preoperative evaluation and prognosis prediction of liver transplant recipients was reviewed, aiming to provide guidance for clinical diagnosis and treatment of liver transplant recipients before and after surgery.

Research methods and progress of gradient multiphase scaffold materials promoting rotator cuff tenon-bone interface repair and regeneration / 中华骨科杂志

Regeneration of rotator cuff tendon-bone interface is crucial in rotator cuff repair. The tendon-bone interface consists of four continuous and gradual regions: the tendon region, the unmineralized fibrocartilage region, the mineralized fibrocartilage region, and the bone region. The development and regeneration of various regions in the tendon-bone interface is regulated by growth factors, inorganic ions, mechanical stimulation, and hypoxic environment. Inspired by factors affecting the development and regeneration of the tendon-bone interface, many researchers have designed gradient scaffold systems that promote regionalized regeneration of the tendon-bone interface. The gradient distribution of these scaffolds includes inorganic ion gradients and growth factor gradients. According to different gradients of the scaffold system, osteogenesis, chondrogenesis and tendon differentiation of cells at the tendon-bone interface are promoted, and the healing of the tendon-bone is synchronously completed to realize the repair and regeneration of the rotator cuff tendon-bone interface. Current studies indicated that gradient multiphase scaffolds had high academic research value and guided significance for future clinical applications in the reconstruction of the tendon-bone interface. In this paper, the factors affecting the development and regeneration of the tendon-bone interface are reviewed, and the effects of these factors on osteogenesis, chondrogenesis and tendon formation of various regions in promoting rotator cuff tendon-bone interface repair are summarized. The properties and effects of reported gradient multiphase scaffolds for rotator cuff injury are discussed, including gradient scaffolds containing inorganic ions and growth factors. Finally, the problems and future development opportunities of gradient multiphase support in rotator cuff repair are summarized.

Progress of anterior gradient protein 2 and anterior gradient protein 3 in the diagnosis and treatment of ovarian cancer / 肿瘤研究与临床

Ovarian cancer ranks the third among gynecological malignancies, while its mortality rate is the highest. Even though recent treatment progress has been made after using PARP inhibitors, the prognosis is still poor. Anterior gradient protein 2 (AGR2) may be a marker for early diagnosis of ovarian cancer, and the expression of AGR2 suggests that the prognosis of ovarian cancer is better. However, Anterior gradient protein 3 (AGR3) could be used to differentiate high-grade and low-grade ovarian cancer, but its influence on prognosis is still controversial. AGR2 and AGR3 may be therapeutic targets for ovarian cancer. This article introduces the research progress of AGR2 and AGR3 in the diagnosis and treatment of ovarian cancer.

Evaluation of different methods for the effective isolation of high-quality DNA from rodent faecal samples

Aims@#The inefficient lysis of recalcitrant bacterial cell wall and subsequent isolation of DNA from environmental samples can lead to a bias in the qualitative and quantitative assessment of bacteria present in the sample. Thus, the selection of an optimum DNA isolation method is the important first step for biosurveillance and metagenomic analyses. This study aims to determine the optimal DNA isolation method out of four commercial DNA isolation kits (A, B, C and D) and two conventional methods (E and F), for rodent faecal droppings. The key selection criterion is the general bacterial diversity contained in the isolated DNA, as evaluated by the Shannon-Weaver index based on the maximal number of PCR-amplicons of partial 16S rRNA gene, derived from each method. The amplicons were separated in accordance with their difference in nucleotide sequences via DGGE. @*Methodology and results@#Five faecal samples of wild rodents were collected from different sites and preserved in DNA/RNA shield reagent (Zymo Research). Each sample was extracted, and the DNA extracts were then subjected to amplification of the bacterial 16S rRNA and DGGE separation of the amplicons. Method E showed a higher yield of DNA (average 324.22 ng/µL) as compared to the other methods. However, the majority of the DNA extracts showed partial degradation. The DGGE profiles showed the highest number of amplicons were generated from DNA extracted from Method A and B with a total of 168 and 167 respectively. This is indicated by the Shannon-Weaver index which were 0.306 and 0.305, respectively. @*Conclusion, significance and impact of study@#Method A is the optimum DNA isolation method for rodent faecal samples as its isolated DNA contains the most diverse bacteria. The isolated DNA can then be used for PCR-biosurveillance or metagenomic sequencing and analyses.

Evaluation for optimization effects of sperm floating plate / 临床检验杂志

Objective To compare the difference between sperm floating plate and density gradient centrifugation combined with swim-up in human sperm preparation.Methods The semen samples were obtained from 50 infertile men in the clinic of Reproductive Medi-cine of Northwest Women's and Children's Hospital excluding azoospermia,severe oligoasthenozoospermia and semen volume less than 2 mL.After semen liquefaction,the differences of sperm concentration,total progressively motile sperm count(TMSC),percentages of progressively motile sperm and normal morphology sperm,recovery rate and DNA fragmentation index(DFI)were measured by both the methods of sperm floating plate and density gradient centrifugation combined with swim-up,and the results were compared.Results Compared with the pre-sorting samples,sperm concentrations[(16.08±13.39)x 106/mL,(8.88±8.06)x 106/mL vs(60.05± 27.21)×106/mL],TMSC[(7.41±6.14)×106,(3.98±3.57)×106vs(22.24±13.74)×106]and DFI[(2.20±3.44)％,(5.20± 10.79)％vs(26.38±13.92)％]in the sorting groups by sperm floating plate and density gradient centrifugation combined with swim-up were decreased significantly,and the percentages of progressive motile sperm[(91.67±4.75)％,(87.86±7.90)％vs(40.21± 16.83)％]and normal morphology sperm[(9.58±5.08)％,(7.72±4.01)％vs(3.58±2.06)％]were increased significantly.Com-pared with the density gradient centrifugation combined with swim-up,the results of sperm floating plate were higher in sperm concen-tration,percentages of progressively motile sperm and normal morphology sperm,TMSC and sperm recovery rate[(30.74±13.70)％vs(17.09±9.20)％],but DFI was lower,time-consuming was shorter[(32.38±1.01)min vs(60.08±2.06)min],and the difference between the two groups was statistically significant(P＜0.05).Conclusion The sperm floating plate may have certain clinical applica-tion prospects in the future due to better parameters of sperm preparation than those of density gradient centrifugation combined with swim-up in simple operation and shorter time-consuming.

Study on Platelet Adhesion and Aggregation Induced by Gradient Shear Stress Using Microfluidic Chip Technology / 中国实验血液学杂志

OBJECTIVE@#To study the effect of gradient shear stress on platelet aggregation by microfluidic chip Technology.@*METHODS@#Microfluidic chip was used to simulate 80% fixed stenotic microchannel, and the hydrodynamic behavior of the stenotic microchannel model was analyzed by the finite element analysis module of sollidwork software. Microfluidic chip was used to analyze the adhesion and aggregation behavior of platelets in patients with different diseases, and flow cytometry was used to detect expression of the platelet activation marker CD62p. Aspirin, Tirofiban and protocatechuic acid were used to treat the blood, and the adhesion and aggregation of platelets were observed by fluorescence microscope.@*RESULTS@#The gradient fluid shear rate produced by the stenosis model of microfluidic chip could induce platelet aggregation, and the degree of platelet adhesion and aggregation increased with the increase of shear rate within a certain range of shear rate. The effect of platelet aggregation in patients with arterial thrombotic diseases were significantly higher than normal group (P<0.05), and the effect of platelet aggregation in patients with myelodysplastic disease was lower than normal group (P<0.05).@*CONCLUSION@#The microfluidic chip analysis technology can accurately analyze and evaluate the platelet adhesion and aggregation effects of various thrombotic diseases unde the environment of the shear rate, and is helpful for auxiliary diagnosis of clinical thrombotic diseases.

Predictive value of quantitative analysis of contrast-enhanced ultrasound gradient features of perfusion-deficient areas in early-stage breast cancer in sentinel lymph node metastasis / 中华超声影像学杂志

Objective:To investigate the predictive value of perfusion defect gradient features of early breast cancer using contrast-enhanced ultrasound (CEUS) in sentinel lymph node (SLN) metastasis.Methods:A retrospective analysis was performed on 147 patients with single early breast cancer confirmed by surgery and pathology in the Affiliated Hospital of Jiangsu University from January 2017 to December 2022, which were divided into SLN positive group (78 cases) and SLN negative group (69 cases) according to whether there are positive lesions in the biopsy SLN. The quantitative characteristics of CEUS in the perfusion defect and marginal high perfusion area of breast cancer in the two groups were analyzed. The differential gradient features between them were analyzed by multivariate Logistic regression and ROC curves.Results:The univariate analysis revealed statistically significant differences between the two groups for peak-arrival time gradient (ΔTTP), peak intensity gradient (ΔPI), ascending branch slope gradient (ΔRS) and area gradient under the curve (ΔAUC) (all P<0.05). Multivariate Logistic regression analysis showed that ΔTTP, ΔPI and ΔAUC were independent predictors of SLN status in early breast cancer (all P<0.05). The sensitivity (74.57%), specificity (84.42%) and area under the curve (0.789) of that combination of the three indexes for predicting SLN status were higher than the prediction efficiency of a single index.In addition, ΔTTP ( r=-0.578, P<0.05) was negatively correlated with average positive rate of SLN, and ΔPI ( r=0.629, P<0.05) and ΔAUC ( r=0.703, P<0.05) were positively correlated with average positive rate of SLN. Conclusions:The perfusion defect gradient features of early breast cancer are closely related to the SLN status and can effectively predict whether SLN metastasis occurrs.

Influence of urbanization on stream fish assemblages in three microbasins in the Upper Paraná River Basin / Influência da urbanização em assembleias de peixes de riachos em três microbacias na bacia do Alto Rio Paraná

Abstract The colonization pattern of fish assemblages in streams is often studied in the context of environmental filters. On the other hand, when fish assemblages are subjected to anthropogenic effects, variables associated with environmental quality assume more importance. Therefore, this work evaluated the richness and composition of fish from streams sampled at different urbanization levels, aiming to determine any direct effects on the structure of fish assemblages. To accomplish this, samples were collected from 2003 to 2011 at 31 sites distributed among 3 microbasins in the Rio Ivinhema Basin, Alto Rio Paraná. Based on environmental variables, physicochemical of the water and analysis of the use and occupation of the soil, the microbasins were classified into different urbanization levels (low, medium and high). A total of 4,320 individuals were sampled, out of which 57 fish species were recorded. Sampled sites with medium urbanization level presented higher richness compared to sampled sites with high urbanization level which presented lower richness. Species richness in these sites was explained mainly by water temperature and water velocity. Results confirmed that urbanization does directly affect environmental integrity, which, in turn, can lead to the homogenization of stream assemblages.

Resumo Estudos sobre assembleias de peixes em riachos enfatizam o papel dos filtros ambientais associados ao padrão de colonização das assembleias, por outro lado, quando a assembleia está sujeita aos efeitos antropogênicos, as variáveis ambientais associadas à qualidade ambiental assumem maior importância. Dessa forma, o objetivo deste estudo foi analisar a riqueza e a composição de peixes de riachos amostrados em diferentes níveis de urbanização, buscando evidenciar se o efeito reflete diretamente na estrutura das assembleias. As amostragens foram realizadas em 31 locais distribuídos em três microbacias na bacia Rio Ivinhema, Alto Rio Paraná, no período de 2003 a 2011. Com base nas variáveis ambientais, físico-químicos da água e análise do uso e ocupação do solo as microbacias foram classificadas em diferentes níveis de urbanização (baixo, médio e alto). Foram amostrados um total 4.320 indivíduos, dos quais foram registradas 57 espécies de peixes. Os locais amostrados com influência média da urbanização apresentaram maior riqueza de espécies, entretanto, os locais amostrados com alta influência da urbanização apresentaram menor riqueza de espécies. Dessa forma, constatamos que a urbanização influencia diretamente na integridade ambiental, que pode levar a homogeneização das assembleias de riachos.