Industrial polyploid yeast strains harbor numerous beneficial traits but suffer from a lack of available auxotrophic markers for genetic manipulation. Here we demonstrated a quick and efficient ...strategy to generate auxotrophic markers in industrial polyploid yeast strains with the RNA-guided Cas9 nuclease. We successfully constructed a quadruple auxotrophic mutant of a popular industrial polyploid yeast strain, Saccharomyces cerevisiae ATCC 4124, with ura3, trp1, leu2, and his3 auxotrophies through RNA-guided Cas9 nuclease. Even though multiple alleles of auxotrophic marker genes had to be disrupted simultaneously, we observed knockouts in up to 60% of the positive colonies after targeted gene disruption. In addition, growth-based spotting assays and fermentation experiments showed that the auxotrophic mutants inherited the beneficial traits of the parental strain, such as tolerance of major fermentation inhibitors and high temperature. Moreover, the auxotrophic mutants could be transformed with plasmids containing selection marker genes. These results indicate that precise gene disruptions based on the RNA-guided Cas9 nuclease now enable metabolic engineering of polyploid S. cerevisiae strains that have been widely used in the wine, beer, and fermentation industries.
Massive open online courses and other forms of remote education continue to increase in popularity and reach. The ability to efficiently proctor remote online examinations is an important limiting ...factor to the scalability of this next stage in education. Presently, human proctoring is the most common approach of evaluation, by either requiring the test taker to visit an examination center, or by monitoring them visually and acoustically during exams via a webcam. However, such methods are labor intensive and costly. In this paper, we present a multimedia analytics system that performs automatic online exam proctoring. The system hardware includes one webcam, one wearcam, and a microphone for the purpose of monitoring the visual and acoustic environment of the testing location. The system includes six basic components that continuously estimate the key behavior cues: user verification, text detection, voice detection, active window detection, gaze estimation, and phone detection. By combining the continuous estimation components, and applying a temporal sliding window, we design higher level features to classify whether the test taker is cheating at any moment during the exam. To evaluate our proposed system, we collect multimedia (audio and visual) data from \text{24} subjects performing various types of cheating while taking online exams. Extensive experimental results demonstrate the accuracy, robustness, and efficiency of our online exam proctoring system.
We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and ...December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15 PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.
Full text
Available for:
CMK, CTK, FMFMET, NUK, UL
RET fusions are present in 1%-2% of non-small-cell lung cancer (NSCLC). Pralsetinib, a highly potent, oral, central nervous system-penetrant, selective RET inhibitor, previously demonstrated clinical ...activity in patients with RET fusion–positive NSCLC in the phase I/II ARROW study, including among treatment-naive patients. We report an updated analysis from the ARROW study.
ARROW is a multi-cohort, open-label, phase I/II study. Eligible patients were ≥18 years of age with locally advanced or metastatic solid tumours and an Eastern Cooperative Oncology Group performance status of 0-2 (later 0-1). Patients initiated pralsetinib at the recommended phase II dose of 400 mg once daily until disease progression, intolerance, consent withdrawal, or investigator’s decision. The co-primary endpoints (phase II) were overall response rate (ORR) by blinded independent central review and safety.
Between 17 March 2017 and 6 November 2020 (data cut-off), 281 patients with RET fusion–positive NSCLC were enrolled. The ORR was 72% 54/75; 95% confidence interval (CI) 60% to 82% for treatment-naive patients and 59% (80/136; 95% CI 50% to 67%) for patients with prior platinum-based chemotherapy (enrolment cut-off for efficacy analysis: 22 May 2020); median duration of response was not reached for treatment-naive patients and 22.3 months for prior platinum-based chemotherapy patients. Tumour shrinkage was observed in all treatment-naive patients and in 97% of patients with prior platinum-based chemotherapy; median progression-free survival was 13.0 and 16.5 months, respectively. In patients with measurable intracranial metastases, the intracranial response rate was 70% (7/10; 95% CI 35% to 93%); all had received prior systemic treatment. In treatment-naive patients with RET fusion–positive NSCLC who initiated pralsetinib by the data cut-off (n = 116), the most common grade 3-4 treatment-related adverse events (TRAEs) were neutropenia (18%), hypertension (10%), increased blood creatine phosphokinase (9%), and lymphopenia (9%). Overall, 7% (20/281) discontinued due to TRAEs.
Pralsetinib treatment produced robust efficacy and was generally well tolerated in treatment-naive patients with advanced RET fusion–positive NSCLC. Results from the confirmatory phase III AcceleRET Lung study (NCT04222972) of pralsetinib versus standard of care in the first-line setting are pending.
•Pralsetinib produced an ORR of 72% in treatment-naive patients with RET fusion–positive NSCLC.•Pralsetinib was generally well tolerated and there were no new safety signals.•The confirmatory phase III AcceleRET Lung study (NCT04222972) of pralsetinib versus standard of care in the first-line setting is ongoing
Pacific white shrimp Litopenaeus vannamei (1050 individuals with initial weight of 1.01 ± 0.001 g) were fed either control diet or one of six dietary astaxanthin (AX) concentration (25, 50, 75, 100, ...125 and 150 mg kg−1) diets for 56 days in 35 tanks (30 shrimp per tank). After 56 days of culture, shrimp‐fed AX125 and AX150 diets had higher (P < 0.05) weight gain, specific growth rate, total antioxidant status and lower (P < 0.05) superoxide dismutase (SOD), catalase (CAT) than shrimp fed control diet. After low dissolved oxygen stress for 1 h, survival rate of shrimp fed AX75, AX100, AX125 and AX150 diets was higher (P < 0.05) than that of shrimp fed control diet. Hypoxia inducible factor‐1α (HIF‐1α), cytosolic manganese superoxide dismutase (cMnSOD) and CAT mRNA expression levels of shrimp fed seven diets were significantly down‐regulated under hypoxia than under normoxia, but their expression levels were higher under hypoxia in shrimp fed AX‐supplemented diets than in shrimp fed control diet. About 70‐kDa heat‐shock protein (Hsp70) mRNA expression level of shrimp fed seven diets was significantly up‐regulated under hypoxia than under normoxia, but its expression level was lower under hypoxia in shrimp fed AX‐supplemented diets than in shrimp fed control diet.
The role of donor lymphocyte infusion (DLI) in the prophylaxis of relapse has not been defined. We retrospectively analyzed the data from 88 patients with advanced-stage acute leukemia after ...HLA-mismatched/haploidentical hematopoietic SCT (HSCT) whose treatment did (n=61) or did not (n=27) include granulocyte CSF (GCSF)-primed PBPCs infusion (GPBPCI). The two groups were compared with respect to relapse and OS. Further, a detailed analysis of risk factors was performed. The 2-year cumulative incidence of relapse in patients receiving prophylactic GPBPCI and not receiving prophylactic GPBPCI were 36% and 55% (P=0.017), respectively. Estimated survival at 3 years was 31% for patients receiving prophylactic GPBPCI and 11% for patients not receiving prophylactic GPBPCI (P=0.001). The three-year probability of leukemia-free survival was also higher in patients who received prophylactic GPBPCI (22%) compared with patients who did not (11%) (P=0.003). Multivariate analysis for relapse showed that use of prophylactic GPBPCI after transplantation was an independent prognostic factor (P=0.025). Higher OS was associated with use of prophylactic GPBPCI (P=0.002), AML (P=0.027) and female sex (P=0.023). Our results suggest that use of prophylactic GPBPCI may increase survival of patients with advanced-stage acute leukemia who receive HLA-mismatched/haploidentical HSCT.
Martensite has a body-centered tetragonal (bct) structure in high carbon steels. However, body-centered cubic (bcc) {112} 〈111〉-type twins instead of bct twins always be observed as the substructure ...of martensite in high carbon steels. In this paper, martensitic substructure in a quenched high carbon Fe-1.4C (wt%) alloy has been investigated in detail using selected area electron diffraction (SAED) technique in a conventional transmission electron microscopy. The reciprocal lattice of martensite has been built based on the experimental SAED patterns. Two sets of diffraction spots (one face-centered cubic lattice and one hexagonal lattice) in the built reciprocal lattice suggest that two crystalline phases with bcc (or α-Fe) and hexagonal (ω-Fe) structure actually coexist in the twinned martensite. The two-phase diffraction spot patterns from the reciprocal lattice can match perfectly with the experimental results. The fact that the {0001}
ω
diffraction spot at the 1/3{222}
α
position and the {0002}
ω
at 2/3{222}
α
can support the ω-Fe existence in the twinned martensite.
Isomerases perform biotransformations without cofactors but often cause an undesirable mixture of substrate and product due to unfavorable thermodynamic equilibria. We demonstrate the feasibility of ...using an engineered yeast strain harboring oxidoreductase reactions to overcome the thermodynamic limit of an isomerization reaction. Specifically, a yeast strain capable of consuming lactose intracellularly is engineered to produce tagatose from lactose through three layers of manipulations. First, GAL1 coding for galactose kinase is deleted to eliminate galactose utilization. Second, heterologous xylose reductase (XR) and galactitol dehydrogenase (GDH) are introduced into the ∆gal1 strain. Third, the expression levels of XR and GDH are adjusted to maximize tagatose production. The resulting engineered yeast produces 37.69 g/L of tagatose from lactose with a tagatose and galactose ratio of 9:1 in the reaction broth. These results suggest that in vivo oxidoreaductase reactions can be employed to replace isomerases in vitro for biotransformation.
We report on a precision energy loss measurement and theoretical investigation of 100 keV/u helium ions in a hydrogen-discharge plasma. Collision processes of helium ions with protons, free ...electrons, and hydrogen atoms are ideally suited for benchmarking plasma stopping-power models. Energy loss results of our experiments are significantly higher than the predictions of traditional effective charge models. We obtained good agreement with our data by solving rate equations, where in addition to the ground state, also excited electronic configurations were considered for the projectile ions. Hence, we demonstrate that excited projectile states, resulting from collisions, leading to capture-, ionization-, and radiative-decay processes, play an important role in the stopping process in plasma.
Full text
Available for:
CMK, CTK, FMFMET, NUK, UL
Aims
Secoisolariciresinol (SECO) is increasingly recognized for potential clinical application because of its preventive effects against breast and colon cancers, atherosclerosis and diabetes, and ...its production through biotransformation has been attempted. However, previously reported bacteria all required stringent anaerobic culture conditions, precluding large‐scale production. Here, we report the isolation and characterization of bacteria that produce SECO under less stringent anaerobic culture conditions.
Methods and Results
Using defatted flaxseed as raw material, we isolated a facultative anaerobic bacterium from human faeces that hydrolysed secoisolariciresinol diglucoside‐3‐hydroxy‐3‐methyl glutaric acid (SDG‐HMGA) oligomers in flaxseed to produce SECO. Both conventional assays and 16S rRNA gene sequence analysis demonstrated its close relatedness with Bacteroides uniformis. The transformation efficiency of SDG in defatted flaxseed to SECO was more than 80% by this bacterial strain. We investigated factors that might influence fermentation, such as redox potential and pH, for large‐scale fermentation of defatted flaxseed to produce SECO.
Conclusions
The method to produce SECO through biotransformation of defatted flaxseed with this bacterial strain is highly efficient and economic.
Significance and Impact of the Study
This bacterial strain can transform SDG to SECO under less stringent anaerobic culture conditions, which will greatly facilitate industry‐scale production of SECO.
PDF
