Effect of Si3N4 Additive on Microstructure and Mechanical Properties of Ti(C,N)-Based Cermet Cutting Tools.

Development of high-performance cutting tool materials is one of the critical parameters enhancing the surface finishing of high-speed machined products. Ti(C,N)-based cermets reinforced with and without different contents of silicon nitride were designed and evaluated to satisfy the requirements. In fact, the effect of silicon nitride addition to Ti(C,N)-based cermet remains unclear. The purpose of this study is to investigate the influence of Si3N4 additive on microstructure, mechanical properties, and thermal stability of Ti(C,N)-based cermet cutting tools. In the present work, α-Si3N4 "grade SN-E10" was utilized with various fractions up to 6 wt.% in the designed cermets. A two-step reactive sintering process under vacuum was carried out for the green compact of Ti(C,N)-based cermet samples. The samples with 4 wt.% Si3N4 have an apparent solid density of about 6.75 g/cm3 (relative density of about 98 %); however, the cermet samples with 2 wt.% Si3N4 exhibit a superior fracture toughness of 10.82 MPa.m1/2 and a traverse rupture strength of 1425.8 MPa. With an increase in the contents of Si3N4, the Vickers hardness and fracture toughness of Ti(C,N)-based cermets have an inverse behavior trend. The influence of Si3N4 addition on thermal stability is clarified to better understand the relationship between thermal stability and mechanical properties of Ti(C,N)-based cermets.

Nanocrystalline Alumina-Zirconia-Based Eutectic Ceramics Fabricated with High-Energy Beams: Principle, Solidification Techniques, Microstructure and Mechanical Properties.

Nanocrystalline alumina-zirconia-based eutectic ceramics fabricated with high-energy beams and composed of ultrafine, three-dimensionally entangled, single-crystal domains are a special category of eutectic oxides that exhibit exceptionally high-temperature mechanical properties, such as strength and toughness as well as creep resistance. This paper aims to provide a comprehensive review on the basic principles, advanced solidification processes, microstructure and mechanical properties of alumina-zirconia-based eutectic ceramics, with particular attention to the status of the art on a nanocrystalline scale. Some basic principles of coupled eutectic growth are first introduced based on previously reported models, followed by concise introduction of solidification techniques and the control strategy of solidification behavior from the processing variables. Then, the microstructural formation of nanoeutectic structure is elucidated with regard to different hierarchical scales, and mechanical properties such as hardness, flexural and tensile strength, fracture toughness and wear resistance are discussed in detail for a comparative study. Nanocrystalline alumina-zirconia-based eutectic ceramics with unique microstructural and compositional characteristics have been produced with high-energy beam-based processes, and in many cases, promising improvements in mechanical performance have been reported as contrasting with conventional eutectic ceramics.

A method based on interpretable machine learning for recognizing the intensity of human engagement intention.

To interact with humans more precisely and naturally, social robots need to "perceive" human engagement intention, especially need to recognize the main interaction person in multi-person interaction scenarios. By analyzing the intensity of human engagement intention (IHEI), social robots can distinguish the intention of different persons. Most existing research in this field mainly focus on analyzing whether a person has the intention to interact with the robot while lack of analysis of IHEI. In this regard, this paper proposes an approach for recognizing the engagement intention intensity. Four categories of visual features, including line of sight, head pose, distance and expression of human, are captured, and a CatBoost-based machine learning model is applied to train an optimal classifier for predicting the IHEI on the dataset. The experimental results show that this classifier can effectively predict the IHEI that can be applied into real human-robot interaction scenarios. Moreover, the proposed model is an interpretable machine learning model, where interpretability analysis on the trained classifier has been done to explore the deep associations between input features and engagement intention, thereby providing robust and effective robot social decision-making.

Prospective Study of Low- and Standard-dose Chest CT for Pulmonary Nodule Detection: A Comparison of Image Quality, Size Measurements and Radiation Exposure.

OBJECTIVE: To comprehensively and accurately analyze the out-performance of low-dose chest CT (LDCT) vs. standard-dose CT (SDCT). METHODS: The image quality, size measurements and radiation exposure for LDCT and SDCT protocols were evaluated. A total of 117 patients with extra-thoracic malignancies were prospectively enrolled for non-enhanced CT scanning using LDCT and SDCT protocols. Three experienced radiologists evaluated subjective image quality independently using a 5-point score system. Nodule detection efficiency was compared between LDCT and SDCT based on nodule characteristics (size and volume). Radiation metrics and organ doses were analyzed using Radimetrics. RESULTS: The images acquired with the LDCT protocol yielded comparable quality to those acquired with the SDCT protocol. The sensitivity of LDCT for the detection of pulmonary nodules (n=650) was lower than that of SDCT (n=660). There was no significant difference in the diameter and volume of pulmonary nodules between LDCT and SDCT (for BMI <22 kg/m2, 4.37 vs. 4.46 mm, and 43.66 vs. 46.36 mm3; for BMI ≥22 kg/m2, 4.3 vs. 4.41 mm, and 41.66 vs. 44.86 mm3) (P>0.05). The individualized volume CT dose index (CTDIvol), the size specific dose estimate and effective dose were significantly reduced in the LDCT group compared with the SDCT group (all P<0.0001). This was especially true for dose-sensitive organs such as the lung (for BMI <22 kg/m2, 2.62 vs. 12.54 mSV, and for BMI ≥22 kg/m2, 1.62 vs. 9.79 mSV) and the breast (for BMI <22 kg/m2, 2.52 vs. 10.93 mSV, and for BMI ≥22 kg/m2, 1.53 vs. 9.01 mSV) (P<0.0001). CONCLUSION: These results suggest that with the increases in image noise, LDCT and SDCT exhibited a comparable image quality and sensitivity. The LDCT protocol for chest scans may reduce radiation exposure by about 80% compared to the SDCT protocol.

Osteopontin improves sensitivity to tyrosine kinase inhibitor in lung adenocarcinoma in vitro by promoting epidermal growth factor receptor phosphorylation.

PURPOSE: Tyrosine kinase inhibitors (TKIs) targeting epidermal growth factor receptor (EGFR) improve the prognosis of lung adenocarcinoma (LUAD). However, the factors affecting its clinical efficacy remain unclear. This study aimed to determine the correlation between Osteopontin (OPN) and EGFR, and explore the inhibitory effect of first-generation TKI gefitinib on LUAD cells. METHODS: The correlation between OPN and EGFR was determined through bioinformatics technology, and the clinical information as well as samples of related patients were collected to verify the relationship between them. Using three different NSCLC cell lines A549, H1299 and PC9, we studied the effects of OPN expression and EGFR phosphorylation on the first-generation TKI's efficacy in vitro. RESULTS: Our data revealed that OPN staining positively linked to a more advanced clinical stage. Compared with the control group, LUAD cells with elevated OPN levels are more sensitive to the growth inhibitory effect of TKI. Knocking down of OPN decreased the response of cells to gefitinib. Besides, OPN also upregulated the phosphorylation of EGFR, thereby affecting the effect of TKI. CONCLUSION: OPN enhanced the sensitivity of LUAD cells to gefitinib by promoting EGFR phosphorylation. OPN may be a potential target for evaluating TKI efficacy and a potential target for molecular therapy.

IgG4-Related Disease: A Retrospective Chinese Study of Features and Treatment Response of 98 Patients Including 4 Rare Cases.

The features and treatment of 98 Chinese patients with immunoglobulin G4 (IgG4)-related disease (IgG4-RD) referred to a single tertiary referring centre were reviewed. Patients diagnosed with IgG4-RD according to the comprehensive diagnostic criteria (CDC) were included in the retrospective study from May 2012 to March 2019. We collected data on clinical, laboratory, imaging, histological features and treatment. Totally, 98 patients with IgG4-RD were enrolled. The common clinical manifestations included abdominal pain, salivary gland swelling and lymphadenopathy. 51% of the patients had multiple organs involvement. Lymph nodes, pancreas and salivary glands were most commonly involved. Four rare sites including ulna, cerebellum, scalp, and mammary gland were found. The serum IgG4 level was increased by 85.7%. The serum IgG4 level was positively correlated with the number of involved organs, IgG and IgG4/IgG. Low C3 and C4 levels were observed in 37.5% and 12.2% patients respectively, and all patients with kidney involvement had hypocomplementemia. A total of 54 patients underwent tissue biopsies, and 55.6%, 31.5% and 11.1% cases were diagnosed as definite, probable and possible IgG4-RD, respectively. Eighty-eight patients received glucocorticoids (GCs) therapy. Five patients underwent radical surgery to remove the lesion. 73% of them presented a complete or partial remission. IgG4-RD is a systemic fibroinflammatory disease with involvement of multiple organs throughout the body including some rare sites. Most IgG4-RD patients had increased serum IgG4 levels and patients with kidney involvement showed hypocomplementemia. GCs therapy is effective. More research is needed to provide a more reliable basis for the diagnosis and treatment of patients.

Application of Low Tube Voltage, Low-concentration Contrast Agent Using a 320-row CT in Coronary CT Angiography: Evaluation of Image Quality, Radiation Dose and Iodine Intake.

The effect of low voltage and low concentration contrast agent on image quality of coronary CT angiography, radiation dose and iodine intake was evaluated. A total of 121 patients with body mass index (BMI) <26 kg/m2 and heart rate (HR) <70 beats/min were randomly divided into four groups: group A (n=31, 80 kVp, 270 mgI/mL); group B (n=33, 100 kVp, 270 mgI/mL); group C (n=30, 100 kVp, 320 mgI/mL); group D (n=27, 100 kVp, 400 mgI/mL). The automatic current modulation system and the iterative algorithm for reconstruction were adopted in each group. The CT values and SD values of the aortic root (AR), subcutaneous fat, left coronary artery opening (LCA), and right coronary artery opening (RCA) were measured in all groups, the signal-to-noise ratio (SNR) and contrast noise ratio (CNR) were calculated, and effective radiation dose and iodine intake were recorded. The subjective assessment for image quality was performed by two physicians using a 4-point scale. The results were compared using the one-way ANOVA and rank sum tests. The image quality of the four groups met the clinical diagnostic requirements. The CT values of AR in groups A, B, C, and D were 537.6±71.4, 447.2±81.9, 445.2±64.9 and 518.5±94.9 Hu, respectively, with no significant difference between group A and group D, or between group B and group C, while CT values in groups B and C were significantly lower than those in groups A and D (P<0.05). In groups A, B, C, and D, the LCA SNR values were 22.7±9.1, 23.3±9.1, 23.3±7.7 and 26.6±8.9, and the RCA CNR values were 26.9±9.8, 28.5±11.4, 27.7±8.8 and 32.1±10.6, respectively. The AR visual scores in groups A, B, C and D were 3.8±0.2, 3.9±0.3, 3.9±0.3 and 4.0±0.3, respectively. There were no significant differences in SNR, CNR and visual score among the four groups (P>0.05). The radiation doses in groups A, B, C and D were 2.6±1.4, 3.6±1.8, 4.9±3.5 and 4.9±2.8 mSv, respectively. The radiation dose in group A was significantly less than that in the rest three groups (P<0.05). The iodine intakes in groups A, B, C and D were 14.9±1.5, 15.0±1.5, 17.7±2.0 and 18.1±2.5 g, respectively. There was no significant difference in the intake of iodine between groups C and D, or between groups A and B, while iodine intake in groups A and B were significantly reduced as compared with that in groups C and D (P<0.05). It was concluded that for patients with low BMI and controlled HR, compared to 100 kVp tube voltage combined with multiple concentration contrast agents, 80 kVp combined with 270 mgI/mL contrast agent is enough to ensure the quality of the images, and can reduce the radiation dose significantly, while reducing the amount of iodine intake notably, thus reducing the incidence of adverse reaction.

Prognostic Factors Analysis and Nomogram Construction of Dual Primary Lung Cancer: A Population Study.

As a special type of lung cancer, multiple primary lung cancer (MPLC) has unique biological characteristics, and its research remains limited. The aim of our research was to identify prognostic factors and construct a prognostic nomogram of dual primary lung cancer (DPLC). A population cohort study of patients with DPLC was conducted using the extracted data from the Surveillance, Epidemiology, and End Results (SEER) database. Relevant survival variables were identified using the Cox proportional hazard model. Prognostic nomogram was performed and its predictive performance was validated via the modeling and validating cohort data. Additionally, propensity score matching (PSM) was also applied to evaluate whether surgery affected the OS of this study population. 5411 eligible DPLC patients were included in this study cohort, with 41.0% of 3-year OS rate and 27.7% of 5-year OS rate. Age, sex, race, grade, stage, lymph node (LN) metastasis, histological type, primary site, and surgery were considered to be prognostic factors of OS. The C-indexes of the established nomogram were 0.70 (95% CI (0.69, 0.71)) in the modeling group and 0.70 (95% CI (0.68, 0.72)) in the validation group, which showed an ideal model discrimination ability. AUC and calibration plots of 3- and 5-year OS also proved the good performance of the established nomogram. After 1 : 1 PSM, surgery can potentially reduce the risk of OS (HR = 0.63, 95% CI: 0.56-0.72) of DPLC. The prognostic nomogram with reliable performance was developed to predict 3- and 5-year OS rates, which could assist clinicians to make more reasonable survival prediction for DPLC patients. For patients without absolute surgical contraindications, surgery should be actively considered.

Genome-wide analysis reveals alcohol dehydrogenase 1C and secreted phosphoprotein 1 for prognostic biomarkers in lung adenocarcinoma.

To seek out novel promising biomarkers for predicting lung adenocarcinoma (LUAD) prognosis, we conducted this study. First, 279 upregulated and 37 downregulated differentially expressed genes were obtained from LUAD and para-carcinoma tissues by the Affymetrix GeneChip Human Transcriptome Array. Then, we randomly classified samples of LUAD data set GSE31210 as training and testing sets in a 1:1 ratio. Alcohol dehydrogenase 1C (ADH1C) and secreted phosphoprotein 1 (SPP1) were finally identified correlating with the LUAD survival through least absolute shrinkage and selection operator penalized Cox proportion hazards regression model, and applied to build a 2-gene signature related to prognosis in training set. Univariate and multivariable survival analyses suggested that overall survival (OS) and relapse-free survival (RFS) in the 2-gene signature low-risk group were better than the high-risk group. Kaplan-Meier curves proved that elevated ADH1C expression and reduced SPP1 expression were related to better OS and RFS. Besides, the SPP1 expressed higher in LUAD than para-carcinoma tissues using quantitative reverse transcription polymerase chain reaction assay. Finally, the association between the two genes and clinicopathological parameters in 80 LUAD were analyzed, it is suggested that SPP1 was relevant to epidermal growth factor receptor mutation. These findings indicated that ADH1C and SPP1 might be novel promising biomarkers for predicting LUAD prognosis.

Identification of species and materia medica within Saussurea subg. Amphilaena based on DNA barcodes.

Saussurea is one of the most species-rich genera in the family Asteraceae, where some have a complex evolutionary history, including radiation and convergent evolution, and the identification of these species is notoriously difficult. This genus contains many plants with medical uses, and thus an objective identification method is urgently needed. Saussurea subg. Amphilaena is one of the four subgenera of Saussurea and it is particularly rich in medical resources, where 15/39 species are used in medicine. To test the application of DNA barcodes in this subgenus, five candidates were sequenced and analyzed using 131 individuals representing 15 medical plants and four additional species from this subgenus. Our results suggested that internal transcribed spacer (ITS) + rbcL or ITS + rbcL + psbA-trnH could distinguish all of the species, while the ITS alone could identify all of the 15 medical plants. However, the species identification rates based on plastid barcodes were low, i.e., 0% to 36% when analyzed individually, and 63% when all four loci were combined. Thus, we recommend using ITS + rbcL as the DNA barcode for S. subg. Amphilaena or the ITS alone for medical plants. Possible taxonomic problems and substitutes for medicinal plant materials are also discussed.

Comparison of Various Parameters of DWI in Distinguishing Solitary Pulmonary Nodules.

In order to prospectively assess various parameters of diffusion weighted imaging (DWI) in differential diagnosis of benign and malignant solitary pulmonary nodules (SPNs), 58 patients (40 men and 18 women, and mean age of 48.1±10.4 years old) with SPNs undergoing conventional MR, DWI using b=500 s/mm2 on a 1.5T MR scanner, were studied. Various DWI parameters [apparent diffusion coefficient (ADC), lesion-tospinal cord signal intensity ratio (LSR), signal intensity (SI) score] were calculated and compared between malignant and benign SPNs groups. A receiver operating characteristic (ROC) curve analysis was employed to compare the diagnostic capabilities of all the parameters for discrimination between benign and malignant SPNs. The results showed that there were 42 malignant and 16 benign SPNs. The ADC was significantly lower in malignant SPNs (1.40±0.44)×10-3 mm2/s than in benign SPNs (1.81±0.58)×10-3 mm2/s. The LSR and SI scores were significantly increased in malignant SPNs (0.90±0.37 and 2.8±1.2) as compared with those in benign SPNs (0.68±0.39 and 2.2±1.2). The area under the ROC curves (AUC) of all parameters was not significantly different between malignant SPNs and benign SPNs. It was suggested that as three reported parameters for DWI, ADC, LSR and SI scores are all feasible for discrimination of malignant and benign SPNs. The three parameters have equal diagnostic performance.

New Saussurea (Asteraceae) species from Bogeda Mountain, eastern Tianshan, China, and inference of its evolutionary history and medical usage.

In this study, Saussurea bogedaensis Yu-J. Wang & Jie Chen, a new species from Bogeda Mountain in the eastern part of the Tianshan Mountains, is described and discussed based on evidence in terms of both morphological and genetic data. S. bogedaensis is morphologically similar to S. involucrata, which is distributed in the western part of the Tianshan Mountains, and it is well known because of its beauty, rarity, and medicinal value. The new species is also similar to S. orgaadayi, which is distributed in the nearby Altai Mountains. Our genetic data support the close relationships among these three species. According to their allopathic distributions, we suggest that these three species are derived from the same ancestor but that they differentiated after reaching their current range. In addition, we propose that the new species might serve as an alternative to S. involucrata in medicine due to their very high similarity. However, this species appears to be rare because we only found six mature individuals in the field despite extensive investigations.

Pharmacokinetics of meperidine (pethidine) in rabbit oral fluid: correlation with plasma concentrations after controlled administration.

Oral fluid assays for quantifying drugs are useful in forensic toxicology and drug monitoring. Compared with blood and urine specimens, oral fluid collection is simple, non-invasive, and more difficult to adulterate. Therefore, we investigated whether meperidine and its metabolites could be detected in oral fluid and whether there was a predictable relationship between oral fluid and plasma concentrations. Male New Zealand white rabbits (n = 10) were administered meperidine hydrochloride (20 mg/kg, intravenous). Then, plasma and oral fluid were collected at various time points up to 10 h after administration. We developed a simple and sensitive gas chromatography-mass spectrometry method for the determination of meperidine and normeperidine in oral fluid and plasma. We estimated the apparent pharmacokinetic parameters for meperidine in oral fluid and plasma and determined the ratio and correlation between oral fluid and plasma concentrations. The results demonstrate that this method has excellent specificity, linearity, precision, and recovery. Meperidine and normeperidine were detected in both body fluids; meperidine was the most abundant analyte in oral fluid. The oral fluid-to-plasma drug concentration ratios did not differ significantly over time (p > 0.05). In addition, oral fluid and plasma levels of meperidine and normeperidine were significantly correlated over time (r = 0.713 and 0.725, respectively; p < 0.05). These results provide context for interpreting meperidine and metabolite concentrations in oral fluid and support the utility of oral fluid as an alternative matrix in clinical and forensic testing.

Radiation of members of the Soroserishookeriana complex (Asteraceae) on the Qinghai-Tibetan Plateau and their proposed taxonomic treatment.

The existence of intermediate types is a major obstacle that can hinder the circumscription of species. Elucidating the mechanism responsible for intermediate types is essential for achieving a reasonable taxonomical treatment. In this study, we explored the evolutionary history and taxonomic treatment of the Soroserishookeriana (C.B.Clarke) Stebbins complex, which comprises six named taxa that may be taxonomically distinct and are all native to the Qingha-Tibetan Plateau (QTP). We made an investigation across the distribution range of Soroseris Stebbins and sampled 27 populations, mostly from the complex. Internal transcribed spacer (ITS) and two chloroplast loci were sequenced and analysed using the neighbour-joining and Bayesian inference methods. The resulting phylogenies show no well supported inconsistence in topologies, in line with the lack of incongruence detected by the length difference test. However, all the trees were largely unresolved within S.hookeriana complex, irrespective of the optimality criterion employed. We interpret these results as an experience of radiation, which is a common process for native genera on the QTP. Thus, we suggest that all of the morphotypes might be different forms, generated by incipient speciation due to recent explosive differentiation, possibly triggered by the drastic environmental changes of the QTP. Given their evolutionary history, we propose a pragmatic method for treating all of these species as subspecies with a total of four new combinations.

Application of palatal rugae morphology in forensic identification / Aplicación de la morfología de las rugas palatinas en la identificación forense

To investigate the feasibility of application of digital images of the palatal rugae in forensic identification. One hundred patients, consisting of 50 males and 50 females, who received treatment between January 2015 and June 2015 at Shanxi Medical University Stomatological Hospital, China, were included in this study. High-resolution digital image of the palatal rugae was taken from each patient using a digital SLR camera and then processed using a digital image recognition system, including noise reduction, contrast enhancement, image segmentation, feature extraction, edge detection and information matching. Using an MATLAB software system, match results and the time taken by each operator for information matching were recorded. The digital image recognition system assisted in information matching of the palatal rugae. Three oral physicians had a 100% correction rate in information matching. Two other operators failed in formation matching in one or two cases. The time taken by oral physicians for information matching was shorter than that taken by the other two operators. Unique palatal rugae morphology has gradually become a novel marker for forensic identification. Digital images of the palatal rugae morphology contribute to rapider and more accurate forensic identification.

El objetivo fue investigar la viabilidad de la aplicación de imágenes digitales de rugas palatinas para la identificación forense. Se incluyeron 100 pacientes, 50 hombres y 50 mujeres, que recibieron tratamiento entre enero de 2015 y junio de 2015 en el Hospital Odontológico de la Universidad Médica de Shanxi, China. Se tomaron imágenes digitales de alta resolución de las rugas palatinas de cada paciente utilizando una cámara réflex digital y luego se procesaron mediante un sistema de reconocimiento de imagen digital, incluyendo reducción de sonido, mejora del contraste, segmentación de imágenes, extracción de características, detección de márgenes y coincidencia de la información. Mediante el programa MATLAB se registraron los resultados y el tiempo de cada operador para obtener información coincidente, además se utilizó el sistema de reconocimiento de imágenes digitales para hacer coincidirlas con la información de las rugas palatinas. Tres odontólogos informaron una tasa de corrección del 100 % al realizar cruces de información. Otros dos operadores fracasaron en uno o dos casos. El tiempo asignado por los odontólogos para la coincidencia de la información fue menor al de los otros operadores. La morfología especializada de las rugas palatinas se ha convertido gradualmente en un nuevo marcador para la identificación forense. Las imágenes digitales de la morfología de las rugas palatinas contribuyen a una rápida y precisa identificación forense.

The complete chloroplast genome of the Taiwan red pine Pinus taiwanensis (Pinaceae).

The complete nucleotide sequence of the Taiwan red pine Pinus taiwanensis Hayata chloroplast genome (cpDNA) is determined in this study. The genome is composed of 119,741 bp in length, containing a pair of very short inverted repeat (IRa and IRb) regions of 495 bp, which was divided by a large single-copy (LSC) region of 65,670 bp and a small single-copy (SSC) region of 53,080 bp in length. The cpDNA contained 115 genes, including 74 protein-coding genes (73 PCG species), 4 ribosomal RNA genes (four rRNA species) and 37 tRNA genes (22 tRNA species). Out of these genes, 12 harbored a single intron, and one (rps12) contained a couple of introns. The overall AT content of the Taiwan red pine cpDNA is 61.5%, while the corresponding values of the LSC, SSC and IR regions are 62.2%, 60.6% and 63.6%, respectively. A maximum parsimony phylogenetic analysis suggested that the genus Pinus, Picea, Abies and Larix were strongly supported as monophyletic, and the cpDNA of P. taiwanensis is closely related to that of P. thunbergii.

Effects of ketamine exposure on dopamine concentrations and dopamine type 2 receptor mRNA expression in rat brain tissue.

OBJECTIVE: To explore the effects of ketamine abuse on the concentration of dopamine (DA), a monoamine neurotransmitter, and the mRNA expression of dopamine type 2 (D2) receptors in brain tissue, we used male Wistar rats to model ketamine abuse through chronic intraperitoneal infusion of ketamine across different doses. METHODS: The rats were sacrificed 45 minutes and 1, 2, and 3 weeks after initiating the administration of ketamine or normal saline, as well as 3 days following discontinuation. Brain tissue was harvested to examine the concentration of 2,5-dihydroxyphenylacetic acid and homovanillic acid, the primary metabolites of DA, as well as the expression of D2 receptor mRNA. In addition, behavioral changes were observed within 30 minutes of administration, and withdrawal symptoms were also documented. A factorial experimental design was used to investigate variations and correlations in the primary outcome measures across the four doses and five time points. Brain DA concentrations were significantly higher in the ketamine-treated groups compared with the saline-treated group, with 30 mg/kg > 10 mg/kg > 60 mg/kg > saline (P < 0.05). The D2 receptor mRNA expression exhibited an inverse downregulation pattern, with 30 mg/kg < 10 mg/kg < 60 mg/kg < saline (P < 0.05). In the 10 mg/kg and 30 mg/kg ketamine-treated groups, the DA concentration and D2 receptor mRNA level in the brain tissue correlated with the dose of ketamine (r = 0.752, r = -0.806), but no significant correlation was found in the 60 mg/kg group. RESULT: These findings indicated that chronic dosing with ketamine increased the concentration of DA in rat brain tissue by increasing DA release or interrupting DA degradation. D2 receptor mRNA expression likely decreased because of stimulation with excessive DA. CONCLUSION: High-dose (60 mg/kg) ketamine had potent paralyzing effects on the central nervous system of rats and weakened the excitatory effects of the limbic system. Brain DA and D2 receptor mRNA may be associated with ketamine abuse.

Palatal rugae for the construction of forensic identification / Rugas palatinas en identificación forense

This study aims to explore the role of palatal rugae pattern in forensic identification by coding of palatal rugae characteristics, and to construct a forensic identification system for oral palatal rugae. One hundred models were included in this study for a systemic coding of palatal rugae pattern based on the shape, quantity, location, and distribution of palatal rugae. Among the involved 100 models, palatal rugae types varied among individuals and palatal rugae pattern was different between men and women, even between two sides in the same individual. Palatal rugae pattern can be used for forensic identification of oral soft tissue and this study proposes a new means for the identification by coding of palatal rugae pattern based on the shape, quantity, location and distribution.

Este estudio tuvo como objetivo explorar el patrón de rugas palatinas en la identificación forense mediante la codificación de las características de éstas. Además se elaboró un sistema de identificación forense. Fueron incluidos cien modelos para una codificación sistemática del patrón de rugas palatinas basado en su forma, cantidad, ubicación y distribución. En todos los modelos se identificó una variación entre los individuos y en el patrón entre hombres y mujeres. El patrón de rugas palatinas puede ser utilizado para la identificación forense de tejido blando oral y este estudio propone un método nuevo para codificarlas.

[Distribution of deltamethrin in acute poisoned rats].

OBJECTIVE: To establish an animal model in acute poisoned rat by deltamethrin and an analysis method for determination of deltamethrin by gas chromatography-electron capture detector (GC-ECD) and to study the distribution of deltamethrin in rats in order to provide the references for forensic medicine identification about such cases. METHODS: Rats were administered with deltamethrin of different doses(512 and 1,024 mg/kg) and killed 1.5 h later to be dissected rapidly for tissues (blood, hearts, livers, lungs, kidneys and brains etc.). Samples were dehydrated by anhydrous sodium sulfate and extracted with petroleum ether and acetone (V:V=4:1). The level of deltamethrin was determined by GC-ECD. RESULTS: There was a good separate between deltamethrin and endogenous impurities. The limit of quantification for deltamethrin in blood and liver were 0.1 microg/mL and 0.1 microg/g (S/N> or =10), respectively. The recovery rate of deltamethrin in blood was 91.55%-134.37% and both inter-day and intra-day precisions were less than 5.67%. The distribution of deltamethrin in poisoned rats with 512 mg/kg was as follow: lungs > livers > hearts > kidneys > blood > brains and with 1 024 mg/kg dose was lungs > blood > hearts > kidneys > brains > livers (P<0.05). CONCLUSION: The GC-ECD method is sensitive for determination of deltamethrin. The distribution of deltamethrin in rats has a dose-dependent manner. The study suggests that samples of blood, hearts, livers, lungs, kidneys and brains are suitable for deltamethrin poisoned analysis.

[Stability of estazolam in dog tissues preserved in formaldehyde solution].

OBJECTIVE: To investigate the stability of estazolam in biological samples preserved in formaldehyde solution. METHODS: The dog was given intragastric administration of estazolam with a dose of 37.6 mg/kg and killed 2 h later. Heart, liver, kidney and brain of the dog were cut up into 1 g and preserved in 4% formaldehyde solution respectively. The content of estazolam in biological samples and formaldehyde solution were analyzed by HPLC at different times. RESULTS: The content of estazolam in heart, liver, kidney and brain or in formaldehyde solution reduced gradually followed with the extention of preservation time. At the 63rd day, estazolam content in four tissues were 0.8%, 1.7%, 1.0% and 2.2% of the original content respectively. CONCLUSION: Estazolam in tissues can diffuse into formaldehyde solution and decomposed quickly, so biological samples contained estazolam should not be preserved in formaldehyde solution.