Lymphocyte antigen receptor gene assembly occurs through the process of V(D)J recombination, which is initiated when the RAG endonuclease introduces DNA DSBs at two recombining gene segments to form ...broken DNA coding end pairs and signal end pairs. These paired DNA ends are joined by proteins of the nonhomologous end-joining (NHEJ) pathway of DSB repair to form a coding joint and signal joint, respectively. RAG DSBs are generated in G1-phase developing lymphocytes, where they activate the ataxia telangiectasia mutated (Atm) and DNA-PKcs kinases to orchestrate diverse cellular DNA damage responses including DSB repair. Paradoxically, although Atm and DNA-PKcs both function during coding joint formation, Atm appears to be dispensible for signal joint formation; and although some studies have revealed an activity for DNA-PKcs during signal joint formation, others have not. Here we show that Atm and DNA-PKcs have overlapping catalytic activities that are required for chromosomal signal joint formation and for preventing the aberrant resolution of signal ends as potentially oncogenic chromosomal translocations.
Few data exist in Latin America concerning the association between organophosphate (OP) urinary metabolites and the consumption of fruits and vegetables and other exposure risk variables in ...schoolchildren.
We collected samples of urine from 190 Chilean children aged 6–12years, fruits and vegetables, water and soil from schools and homes, and sociodemographic data through a questionnaire. We measured urinary dialkylphosphate (DAP) OP metabolites and OP pesticide residues in food consumed by these 190 children during two seasons: December 2010 (summer) and May 2011 (fall). We analyzed the relationship between urinary DAP concentrations and pesticide residues in food, home pesticide use, and residential location.
Diethylalkylphosphates (DEAP) and dimethylalkylphosphates (DMAP) were detected in urine in 76% and 27% of the samples, respectively. Factors associated with urinary DEAP included chlorpyrifos in consumed fruits (p<0.0001), urinary creatinine (p<0.0001), rural residence (p=0.02) and age less than 9years (p=0.004). Factors associated with urinary DMAP included the presence of phosmet residues in fruits (p<0.0001), close proximity to a farm (p=0.002), home fenitrothion use (p=0.009), and season (p<0.0001).
Urinary DAP levels in Chilean school children were high compared to previously reported studies. The presence of chlorpyrifos and phosmet residues in fruits was the major factor predicting urinary DAP metabolite concentrations in children.
► Chilean children had higher levels of OP metabolites than most published studies. ► Exposure during both summer and fall regardless of regional peaks in agriculture. ► OP residues in fruits were the major predictor of urinary DAP metabolites. ► First data on OP metabolites and dietary exposure in children of Latin America.
As healthcare systems are adapting due to COVID-19, there has been an increased need for telehealth in the outpatient setting. Not all patients have been comfortable with this transition. We sought ...to determine the relationship between health literacy and technological comfort in our cancer patients.
We conducted a survey of patients that presented to the oncology clinics at a single-center over a 2-month period. Patients were given a voluntary, anonymous, survey during their visit containing questions regarding demographics, health literacy and technological comfort.
344 surveys were returned (response-rate 64.3%). The median patient age was 61 years, 70% of responders were female and the most common race was White (67.3%). Increasing patient age, male gender, Black and Native-American race, decreased health literacy and lack of home broadband were associated with lower technological comfort score.
In our cohort, patients with lower health literacy scores, older and male patients, or who have poor internet access showed a lower level of technological comfort. At risk patients can be identified and provided additional support in their use of telehealth services.
•As healthcare systems adapt, there has been an increased use of telemedicine.•Patients with poor health literacy were likely to have reduced technological comfort.•It is important to identify these at-risk patients and assist them in utilizing telehealth services.
Medical countermeasures (MCMs) for hematopoietic acute radiation syndrome (H-ARS) should be evaluated in well-characterized animal models, with consideration of at-risk populations such as ...pediatrics. We have developed pediatric mouse models of H-ARS and delayed effects of acute radiation exposure (DEARE) for efficacy testing of MCMs against radiation. Male and female C57BL/6J mice aged 3, 4, 5, 6, 7 and 8 weeks old (±1 day) were characterized for baseline hematopoietic and gastrointestinal parameters, radiation response, efficacy of a known MCM, and DEARE at six and 12 months after total-body irradiation (TBI). Weanlings (age 3 weeks) were the most radiosensitive age group with an estimated LD50/30 of 712 cGy, while mice aged 4 to 8 weeks were more radioresistant with an estimated LD50/30 of 767-787 cGy. Female weanlings were more radiosensitive than males at 3 and 4 weeks old but became significantly more radioresistant after the pubertal age of 5 weeks. The most dramatic increase in body weight, RBC counts and intestinal circumference length occurred from 3 to 5 weeks of age. The established radiomitigator Neulasta® (pegfilgrastim) significantly increased 30-day survival in all age groups, validating these models for MCM efficacy testing. Analyses of DEARE among pediatric survivors revealed depressed weight gain in males six months post-TBI, and increased blood urea nitrogen at 12 months post-TBI which was more severe in females. Hematopoietic DEARE at six months post-TBI appeared to be less severe in survivors from the 3- and 4-week-old groups but was equally severe in all age groups by 12 months of age. Similar to our other acute radiation mouse models, there was no appreciable effect of Neulasta used as an H-ARS MCM on the severity of DEARE. In summary, these data characterize a pediatric mouse model useful for assessing the efficacy of MCMs against ARS and DEARE in children.
Mycotoxin contamination in animal milk is an emerging concern around the globe. Here we developed and validated an ultrahigh-performance liquid chromatography and mass spectrometry-selected reaction ...monitoring (UHPLC/MS-SRM) method to quantify low concentrations of aflatoxins (AFs) and ochratoxins (OTs) in routinely consumed animal milk samples collected from southern India. Stable isotope dilution methodology was applied to quantify AFB
1
, AFB
2
, AFG
1
, AFG
2
, AFM
1
, AFM
2
and OTA, OTB in
n
= 38 different milk samples, using 1 mL of milk. Bioanalytical parameters including method accuracy, precision, recovery, regression analysis and stability were assessed. Dynamic ranges for quantification were between 15.6–1000 pg/mL for AFB
1
, AFB
2
, AFG
1
, and OTA; 7.8–500 pg/mL for AFM
1
, AFM
2
and OTB; 78.6–5000 pg/mL for AFG
2
. Method accuracy ranged between 80–120%, with ± 15% precision. Recoveries for spiked standards were > 88% in water and 75% in milk, with limits of quantification (LOQ) ranging between 31.3 pg/mL for AFB
1
, AFB
2
, AFG
1
and OTA, 15.6 pg/mL for AFM
1
, AFM
2
and OTB and 156 pg/mL for AFG
2
. R
2
values for regression analyses ranged between 0.9991–0.9999. AFB
2
mean: 38 pg/mL (0.038 µg/kg) was quantified in goat milk, AFM
1
was quantified in cow, goat, pasteurized milk mean: 331 pg/mL (0.331 µg/kg), 406 pg/mL (0.406 µg/kg), 164 pg/mL (0.164 µg/kg). Additionally, 90% of cow, goat and pasteurized milk samples were above European Union (EU) limits of 50 pg/mL (0.05 µg/kg) and 40% of cow and goat milk samples were above the Food Safety Standards Authority of India (FSSAI) limit of 500 pg/mL (0.5 µg/kg). AFM
2
was also quantified in cow, goat, and pasteurized milk samples mean: 249 pg/mL (0.249 µg/kg), 375 pg/mL (0.375 µg/kg), 81 pg/mL (0.081 µg/kg). Our dynamic ranges for quantification are lower than other published methods, with need for a smaller volume of milk. This validated method can be applied for routine quantification of mycotoxins in milk.
The structure of titanyl phthalocyanine (TiOPc) thin films is correlated with photovoltaic properties of planar heterojunction solar cells by pairing different TiOPc polymorph donor layers with C60 ...as an acceptor. Solvent annealing and the insertion of two different templating layers, namely 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS) and CuI, prove to be effective methods to control the TiOPc thin film structure. The crystal phase of TiOPc thin films was identified by combining X-ray reflectivity (XRR) measurements with spectroscopic techniques, including absorption and micro-Raman measurements. Implementation of a donor layer with an absorption spectrum extending into the near-infrared (NIR) led to solar cells with external quantum efficiencies (EQEs) above 27% from λ = 600 – 890 nm, with the best device yielding a power conversion efficiency (PCE) of 2.6%. Our results highlight the need to understand the relationship between processing parameters and thin film structure, as these have important consequences on device performance.
Purpose: We aim to compare the incidence of corneal epithelial defects after laser for retinopathy of prematurity (ROP) with and without the use of postoperative erythromycin ointment. Methods: In ...this retrospective observational cohort study, a total of 100 infants (200 eyes) consecutively treated with laser for ROP between 2012 and 2018. The primary outcome was presence or absence of corneal epithelial defect using fluorescein on bedside examination within the first week following laser for ROP. Additional data assessed included: the use of postoperative prophylactic erythromycin ointment for 1 week, postoperative day on which examination using fluorescein occurred, presence of corneal opacity, gender, birth weight, and gestation age. The presence or absence of postoperative corneal epithelial defects was compared between eyes receiving postoperative erythromycin ointment or not using a Fisher's exact test. Results: Postoperative corneal epithelial defects were more common in eyes which did not receive postoperative erythromycin (7 of 40 eyes; 17.5%), compared to eyes which did receive erythromycin (1 of 160 eyes; 0.6%; P < 0.0001). Postoperative bedside examinations with fluorescein were performed within 2 days of surgery on 136 of 200 of eyes (68%). Corneal opacities were noted in 3 of 200 eyes (1.5%). Conclusion: We observed less corneal epithelial defects in eyes which received postoperative erythromycin ointment for 1 week after laser for ROP than in those which did not. While multiple variables may influence the presence or absence of postoperative corneal epithelial defects following laser for ROP, consideration for postoperative lubricating ointment following laser for ROP seems reasonable.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Green Lithography for Delicate Materials Grebenko, Artem; Bubis, Anton; Motovilov, Konstantin ...
Advanced functional materials,
07/2021, Letnik:
31, Številka:
27
Journal Article
Recenzirano
Odprti dostop
A variety of unconventional materials, including biological nanostructures, organic and hybrid semiconductors, as well as monolayer, and other low‐dimensional systems, are actively explored. They are ...usually incompatible with standard lithographic techniques that use harsh organic solvents and other detrimental processing. Here, a new class of green and gentle lithographic resists, compatible with delicate materials and capable of both top‐down and bottom‐up fabrication routines is developed. To demonstrate the excellence of this approach, devices with sub‐micron features are fabricated on organic semiconductor crystals and individual animal's brain microtubules. Such structures are created for the first time, thanks to the genuinely water‐based lithography, which opens an avenue for the thorough research of unconventional delicate materials at the nanoscale.
A genuinely water‐based eco‐friendly lithographic approach is demonstrated, where chitosan derivatives act as an e‐beam/ deep ultraviolet resist. The chelation of chitosan derivatives facilitates patterning at the nanoscale without any harsh solvents or physical treatments of the surface. Both bottom‐up and top‐down processes are implemented directly on the surface of unconventional delicate materials, owing to the ultimate cleanliness of the developed regions.
Organic photovoltaic cells possess desirable practical characteristics, such as the potential for low‐cost fabrication on flexible substrates, but they lag behind their inorganic counterparts in ...performance due in part to fundamental energy loss mechanisms, such as overcoming the charge transfer (CT) state binding energy when photogenerated charge is transferred across the donor/acceptor interface. However, recent work has suggested that crystalline interfaces can reduce this binding energy due to enhanced CT state delocalization. Solar cells based on rubrene and C60 are investigated as an archetypal system because it allows the degree of crystallinity to be moldulated from a highly disordered to highly ordered system. Using a postdeposition annealing method to transform as‐deposited amorphous rubrene thin films into ones that are highly crystalline, it is shown that the CT state of a highly crystalline rubrene/C60 heterojunction undergoes extreme delocalization parallel to the interface leading to a band‐like state that exhibits a linear Stark effect. This state parallels the direct charge formation of inorganic solar cells and reduces energetic losses by 220 meV compared with 12 other archetypal heterojunctions reported in the literature.
Highly crystalline organic solar cells are investigated, and reduced voltage loss attributed to a band‐like charge transfer state is found.
The first variational calculations of the rotational-vibrational levels of PF
are performed and intensities for dipole transitions between them computed. This is accomplished using new state of the ...art potential energy and dipole moment surfaces. This allows the infrared spectrum of PF
to be simulated, providing a complete overview of the ro-vibrational spectrum up to J=100 in the wavenumber range 0-3100 cm
−1
. The behaviour of PF
at high rotational excitations is also investigated. The formation of quasi-degenerate 6-fold rotational energy clusters at high rotational excitation are investigated up to J=270 and are found to occur around J=200. The clustering effect is analysed in terms of semi-classical rotational energy surfaces.
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