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Y chromosomal short tandem repeats (Y-STRs) have been applied overwhelmingly in forensic areas for solving paternity identification and sexual assault cases. Yet the widely used Y-STR kits contain mostly single-copy markers, which may restrict the discrimination power. Here, a novel Y-STR multiplex was developed and validated in order to complement the currently available Y-STR kits, especially on differentiating male relatives. The assay includes twelve multicopy Y-STR loci (DYF371, DYF383S1, DYS385, DYF387S1, DYS389I/II, DYF399S1, DYF404S1, DYF409S1, DYF411S1, DYS464, DYS526, DYS527; four of them are rapidly mutating ones), 1 single-copy Y-STR (DYS391), and Amelogenin, and was optimized to amplify at annealing temperature of 59°C and 28 cycles. Validation studies show that full profiles are obtained with 0.125 ng of male DNA. The system is capable of overcoming high concentrations of inhibitors such as hematin, EDTA, and humic acid. Besides, the results demonstrate good sizing precision and the ability to detect male-specific profiles in male/female DNA mixtures at a ratio of 1:800. Excellent species specificity was also observed in microorganisms and non-primates, while detectable peaks were found in some primates. Based on published genetic data, gene diversity values were above 0.7 for most of the loci in our multiplex, inferring a high capacity in discriminating unrelated and related male individuals. The kit is of great potential for forensic application.

Nowadays, kinship testing is very common in forensic caseworks, but the power of autosomal short tandem repeats (A-STRs) may be limited in complex cases. X-Chromosome short tandem repeats (X-STRs), having a unique heritage mode, should be of special use in some deficient cases. To evaluate and compare the potential of A-STR and X-STR as supplement genetic markers in deficient kinship testing, we simulated 10,000 duos for each of 18 kinds of relationships involving full sibling, half-sibling, grandparent-grandchild, and uncle/aunt-nephew/niece. Loci from STRTyper10, PowerPlex 16, and Investigator Argus X-12 were studied in Southern Han Chinese and the distribution of likelihood ratio (LR) values was analysed. With the addition of the X-12 system, the distribution of LR values for the full sisters, paternal half-sisters, paternal grandmother-granddaughters, maternal aunt-nieces, and maternal aunt-nephews separated much more obviously from those of unrelated duos, and the effectiveness was 1.0000, 0.99865, 0.9991, 0.8996 and 0.9634, respectively, which was more efficient than A-STRs. For the individual duos with other relationships, the effects of adding X-STRs and A-STRs were similar. Therefore, for the Southern Han Chinese, X-STRs can be very useful in kinship testing involving full sisters, paternal half-sisters, paternal grandmother-granddaughters, and maternal aunt-nieces/nephews.

Novel Y chromosomal STR (Y-STR) markers have been continuously discovered during the past decades, promoting the widely application of Y-STRs in the area of forensic science. Here, four multicopy Y-STR markers were focused, including DYF383S1, DYF409S1, DYF411S1 and DYF371, which are rarely reported in China and differ in the number of copies on Y chromosome. Characterization of the markers was performed in population of Hunan province, China, based on sequence analysis. Allele nomenclature and allelic ladder were then developed to avoid the disunity of typing standard. To evaluate their forensic performance, gene diversity of the four loci was investigated in 548 unrelated male individuals from Hunan population. The number of haplotype was analyzed by both conservative (C-type) and expanded approach (E-type) for markers containing more than 2 copies. As detected, there were 7, 9, 13 alleles and 15, 22, 23 haplotypes for DYF383S1, DYF409S1 and DYF411S1, respectively. Thirty-two C-types and 56 E-types were found in DYF371, indicating the highest haplotype diversity (HD) among all tested loci (0.871 and 0.888 for C-type and E-type, respectively). Two other Y-STRs (DYF409S1, DYF411S1) also showed high haplotype diversity (>0.8) in the population. Combining the four loci, discrimination capacity reached 0.505 (C-type) or 0.533 (E-type), and the total HD values exceeded 0.991. The results inferred great potential of the multicopy markers to improve the resolution of paternal identification in China population.

With a unique inheritance pattern compared to autosomal short tandem repeats (A-STRs), X chromosomal STRs (X-STRs) have special usage in forensic relationship testing. In this study, we designed a multiplex amplification system (named TYPER-X19 multiplex assay) consisting of 18 STR loci spreading from 7.837 to 149.460 Mb on the X chromosomes (DXS9895, DXS8378, DXS9902, DXS6810, DXS7132, DXS10079, DXS6789, DXS7424, DXS101, DXS6797, DXS7133, DXS6804, GATA165B12, DXS10103, HPRTB, GATA31E08, DXS8377, and DXS7423), and the amelogenin. PCR primers were marked with four kinds of fluorophores including FAM, HEX, TAMRA, and ROX. The multiplex system was optimized and tested for precision, concordance, reproducibility, sensitivity, stability, DNA mixture, and species specificity according to the conventional validation guidelines. The results indicated that the system was accurate, reliable, and sensitive enough, and was suitable for common forensic case-type samples. In the population genetic study, a total of 148 alleles were detected at the 18 X-STR loci in 398 Southern Han Chinese. Relatively high combined power of discrimination in male (PDm ), power of discrimination in female (PDf ), mean paternity exclusion chance in trios (MECtrio ), and mean paternity exclusion chance in duos (MECDuo ) by Desmarais were detected, and HPRTB-DXS10103 was in linkage disequilibrium. The results suggested that the TYPER-X19 multiplex assay was suitable for forensic applications.

Remarkable progress has been made in recent years on the research of body fluid identification through messenger RNA(mRNA) profiling. In order to examine the viability of mRNA profiling as a method to identify aged bloodstains, this study tested two groups of bloodstain samples, dated 30 years and 50 years back respectively, on seven blood specific markers, i.e. HBB, HBA, GYPA, CD93, ALAS2, SPTB (91 bp and 247 bp primers), and PBGD. Test results indicate that HBA and HBB are the most stable markers in aged bloodstains, returning positive results in over 80% of the 50-year-old samples and over 90% of the 30-year-old samples. This finding proves mRNA profiling an effective way of identifying aged bloodstains.

Based on the analysis of time series characteristics of production process based on common batch process end point quality prediction a predictive model based on bidirectional gated loop neural network is proposed to predict final product quality for unequal interval batch processes. Based on the requirement of forecasting value in actual production, loss function adapted to batch process is constructed, which makes model meet forecasting requirement under guarantee prediction precision, thus obtaining greater production benefit. Two-way gated loop (GRU) neural networks with different loss functions are compared with multi-directional partial least squares (MPLS) neural networks support vector regression SVR and gated cyclic unit neural networks. Results show that bidirectional gated loop neural networks have stronger applicability and higher accuracy.

In this study, the complete mitochondrial genome (mtGenome) of six samples from three forensic cases was sequenced using the Ion Torrent Personal Genome Machine (PGM). The analyzed samples from forensic cases included bloodstains from several materials, such as gauze, Flinder's Technology Associates (FTA) cards and swabs. The age of the samples ranged from two months to twelve years. The complete mtGenomes were amplified using the tiling sequencing strategy which divided the whole mtGenome into 162 amplicons. All amplicons were successfully recovered. A phylogenetic analysis was performed to determine the accuracy of the PGM data, and which were compared to partial Sanger-based sequencing data. The average coverage of the PGM data were above 4000× in all case samples, and 99.86% concordance was observed using both sequencing methods. In conclusion, we demonstrate the ability to recover the complete mtGenome from bloodstains with relatively poor DNA quality by PGM. Moreover, the results are concordant with Sanger sequencing data. This new method has potential use in forensic practice.

Haplotypes of DYS389I, YS389II, DYS439, DYS438, DYS392, DYS393, DYS19, DYS390, DYS391, DYS385 were determined from 136 unrelated Chinese male individuals.