Next-generation sequencing to detect circulating tumor DNA is a minimally invasive method for tumor genotyping and monitoring therapeutic response. The majority of studies have focused on detecting circulating tumor DNA from patients with metastatic disease. Herein, we tested whether circulating tumor DNA could be used as a biomarker to predict relapse in triple-negative breast cancer patients with residual disease after neoadjuvant chemotherapy. In this study, we analyzed samples from 38 early-stage triple-negative breast cancer patients with matched tumor, blood, and plasma. Extracted DNA underwent library preparation and amplification using the Oncomine Research Panel consisting of 134 cancer genes, followed by high-coverage sequencing and bioinformatics. We detected high-quality somatic mutations from primary tumors in 33 of 38 patients. TP53 mutations were the most prevalent (82%) followed by PIK3CA (16%). Of the 33 patients who had a mutation identified in their primary tumor, we were able to detect circulating tumor DNA mutations in the plasma of four patients (three TP53 mutations, one AKT1 mutation, one CDKN2A mutation). All four patients had recurrence of their disease (100% specificity), but sensitivity was limited to detecting only 4 of 13 patients who clinically relapsed (31% sensitivity). Notably, all four patients had a rapid recurrence (0.3, 4.0, 5.3, and 8.9 months). Patients with detectable circulating tumor DNA had an inferior disease free survival (p < 0.0001; median disease-free survival: 4.6 mos. vs. not reached; hazard ratio = 12.6, 95% confidence interval: 3.06–52.2). Our study shows that next-generation circulating tumor DNA sequencing of triple-negative breast cancer patients with residual disease after neoadjuvant chemotherapy can predict recurrence with high specificity, but moderate sensitivity. For those patients where circulating tumor DNA is detected, recurrence is rapid.

Domestic chickens are excellent models for investigating the genetic basis of phenotypic diversity, as numerous phenotypic changes in physiology, morphology, and behavior in chickens have been artificially selected. Genomic study is required to study genome-wide patterns of DNA variation for dissecting the genetic basis of phenotypic traits. We sequenced the genomes of the Silkie and the Taiwanese native chicken L2 at ∼23- and 25-fold average coverage depth, respectively, using Illumina sequencing. The reads were mapped onto the chicken reference genome (including 5.1% Ns) to 92.32% genome coverage for the two breeds. Using a stringent filter, we identified ∼7.6 million single-nucleotide polymorphisms (SNPs) and 8,839 copy number variations (CNVs) in the mapped regions; 42% of the SNPs have not found in other chickens before. Among the 68,906 SNPs annotated in the chicken sequence assembly, 27,852 were nonsynonymous SNPs located in 13,537 genes. We also identified hundreds of shared and divergent structural and copy number variants in intronic and intergenic regions and in coding regions in the two breeds. Functional enrichments of identified genetic variants were discussed. Radical nsSNP-containing immunity genes were enriched in the QTL regions associated with some economic traits for both breeds. Moreover, genetic changes involved in selective sweeps were detected. From the selective sweeps identified in our two breeds, several genes associated with growth, appetite, and metabolic regulation were identified. Our study provides a framework for genetic and genomic research of domestic chickens and facilitates the domestic chicken as an avian model for genomic, biomedical, and evolutionary studies.

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The new portable microAeth ® AE51 (AE51) is very useful for assessing occupational and environmental exposure to black carbon (BC) aerosols in epidemiological research. However, information about the performance of AE51 is limited. This study compares AE51 with the widely used, rack-mounted Aethalometer ® AE31 (AE31) by evaluating the real-time performance of these two instruments, as carried out at a traffic site. Additionally, an optimized noise-reduction averaging (ONA) algorithm is adopted to eliminate the negative values in the BC data sets. Negative BC levels may be present using AE51 at low actual BC levels or at a high time-resolution. The negative values can be eliminated very effectively by the ONA method. The time-variation of the 5 min BC levels measured using AE51 is highly consistent with that measured using AE31. Loading effects on the measured BC levels are observed during the sampling period. Additionally, the correcting factor, k, is evaluated, in which the correcting factors are 0.0033 and 0.0039 for AE31 and AE51, respectively, when used to monitor the BC levels at this traffic site. The analytical results indicate that the BC levels are underestimated by up to 15% when the ATN-ATN 0 increases to ~40. The measurement results also reveal that the BC levels measured by AE51 are approximately 14% higher than those measured using AE31. These results may be due to the different aerosol deposition velocities and mass attenuation cross-section parameters (σ ATN ) of the two instruments.

The Taipei main station is a major transfer station in the Taipei Rapid Transit System and is located at the center of Taipei metropolitan areas. This study investigates particle mass concentrations and size distributions at the concourse in this underground station using an optical particle counter. On-site measurements were taken during January-February 2008. Experimental results show that PM 10 and PM 2.5 levels in the Taipei main station were 9.83-104.26 μg/m 3 and 3.84-59.74  μg/m 3 , respectively. The lognormal mass size distribution in the Taipei main station had two modes; one near 0.27 μm and the other at about 12.5 μm. Additionally, the mean mass concentrations were governed by particles with coarse PM. Measurement results also suggest that average PM 10 and PM 2.5 levels in the indoor station were about 0.70 and 0.53 times those outdoors, respectively. The PM levels in the indoor station and outdoors were positively correlated, indicating that PM levels at the concourse in the Taipei main station are significantly influenced by outdoor ambient PM levels. Moreover, the low PM 2.5 -to-PM 10 ratio at the concourse in the Taipei main station was likely the result of coarse PM being re-suspended in the station concourse due to passenger movement.

Current antiviral therapy fails to cure chronic hepatitis B virus (HBV) infection because of persistent covalently closed circular DNA (cccDNA). CRISPR/Cas9-mediated specific cleavage of cccDNA is a potentially curative strategy for chronic hepatitis B (CHB). However, the CRISPR/Cas system inevitably targets integrated HBV DNA and induces double-strand breaks (DSBs) of host genome, bearing the risk of genomic rearrangement and damage. Herein, we examined the utility of recently developed CRISPR/Cas-mediated "base editors" (BEs) in inactivating HBV gene expression without cleavage of DNA. Candidate target sites of the SpCas9-derived BE and its variants in HBV genomes were screened for generating nonsense mutations of viral genes with individual guide RNAs (gRNAs). SpCas9-BE with certain gRNAs effectively base-edited polymerase and surface genes and reduced HBV gene expression in cells harboring integrated HBV genomes, but induced very few insertions or deletions (indels). Interestingly, some point mutations introduced by base editing resulted in simultaneous suppression of both polymerase and surface genes. Finally, the episomal cccDNA was successfully edited by SpCas9-BE for suppression of viral gene expression in an in vitro HBV infection system. In conclusion, Cas9-mediated base editing is a potential strategy to cure CHB by permanent inactivation of integrated HBV DNA and cccDNA without DSBs of the host genome.

The effect of solid particle loading on the collection efficiency of a single-stage impactor with different impaction surface designs has been investigated. Experimental results show that the time-varying collection efficiency depends on the surface coating condition, thickness of particle deposit, and impaction surface design. Deposited particles change the surface condition such that the particle collection efficiency decreases with time for the coated impaction surface while it increases with time for the uncoated impaction surface. However, after heavy loading, the collection efficiency eventually approaches nearly the same asymptotic value whether the impaction surface is coated or not. The impaction surface with an inverted conical cavity and an orifice plate alleviates particle bounce and reentrainment problems during particle collection process, resulting in .a much greater collection efficiency than the conventional design, which uses flat impaction surface.

Platinum (Pt) drugs are the most potent and commonly used anti-cancer chemotherapeutics. Nanoformulation of Pt drugs has the potential to improve the delivery to tumors and reduce toxic side effects. A major challenge for translating nanodrugs to clinical settings is their rapid clearance by the reticuloendothelial system (RES), hence increasing toxicities on off-target organs and reducing efficacy. We are reporting that an FDA approved parenteral nutrition source, Intralipid 20%, can help this problem. A dichloro (1, 2-diaminocyclohexane) platinum (II)-loaded and hyaluronic acid polymer-coated nanoparticle (DACHPt/HANP) is used in this study. A single dose of Intralipid (2 g/kg, clinical dosage) is administrated [intravenously (i. v.), clinical route] one hour before i.v. injection of DACHPt/HANP. This treatment can significantly reduce the toxicities of DACHPt/HANP in liver, spleen, and, interestingly, kidney. Intralipid can decrease Pt accumulation in the liver, spleen, and kidney by 20.4%, 42.5%, and 31.2% at 24-hr post nanodrug administration, respectively. The bioavailability of DACHPt/HANP increases by 18.7% and 9.4% during the first 5 and 24 hr, respectively.