Effects of dietary supplementation of Anabaena sp. PCC7120 expressing VP28 protein on survival and histopathology after WSSV infection in Macrobrachium nipponense.

Shrimp are especially susceptible to the White Spot Syndrome Virus (WSSV). Oral administration of the WSSV envelop protein VP28 is a promising approach to protect shrimp against WSSV. In this study, Macrobrachium nipponense (M. nipponense) were fed for 7 days with food supplemented with Anabaena sp. PCC 7120 (Ana7120) expressing VP28 and then challenged with WSSV. The survival rates of M. nipponense in three groups, including control, WSSV-challenged, and VP28-vaccinated, were subsequently determined. We also determined the WSSV content of different tissues and the tissue morphology in the absence of and after viral challenge. The survival rate of the positive control group (no vaccination and challenge, 10%) and empty vector group (fed with Ana7120 pRL-489 algae and challenged, 13.3%) was much lower than the survival rate of M. nipponense in wild type group (fed with Ana7120 and challenged, 18.9%), immunity group 1 (fed with 3.33% Ana7120 pRL-489-vp28 and challenged, 45.6%) or immunity group 2 (fed with 6.66% Ana7120 pRL-489-vp28 and challenged, 62.2%). RT-qPCR showed that WSSV content of the gill, hepatopancreas and muscle of immunity groups 1 and 2 were substantially lower than the positive control. Microscopic examination revealed that WSSV-challenged positive control exhibited large number of cell rupture, necrosis, nuclear exfoliation in gills and hepatopancreatic tissues. The gill and hepatopancreas of immunity group 1 showed partial symptoms of infection, yet the tissue was visibly healthier than that of the positive control group. No symptoms were visible in the gills and hepatopancreatic tissue of immunity group 2. The results demonstrate that the probability of M. nipponense infected by WSSV can be diminished by oral administration of cyanobacteria-expressed VP28. Such an approach could improve the disease resistance and delay the death of M. nipponense in the commercial production of this shrimp.

Oral administration of Synechococcus sp. PCC7942 trans-vp19 and trans-vp (19+28) genes improve the immune and antioxidant capacity in Procambarus clarkii under white spot syndrome virus stress.

This study aimed to evaluate antioxidant capacity and protection from white spot syndrome virus (WSSV) challenge of Procambarus clarkii fed trans-vp19 and trans-vp (19 + 28) genes of Synechococcus sp. PCC7942 (Syn7942). P. clarkii were fed transgenic cyanobacteria continuously for 7 days, and then infected with WSSV after 12 h starvation. The daily mortality in each group was measured for 10 days and hepatopancreas and muscle of P. clarkii were examined for enzymes phenoloxidase (PO) activity, catalase (CAT) activity, glutathione peroxidase (GSH-px) activity, and malondialdehyde (MDA) concentration after immunization and viral challenge at different times. Compared with the WSSV-infected crayfish in positive control group (challenge and no vaccination) and wild type group (challenge, feeding wild-type Syn7942), vp19 group (challenge, feeding Syn7942 trans-vp19 gene) and vp (19 + 28) group [challenge, feeding Syn7942 trans-vp (19 + 28) genes] significantly improved the survival rate from 0% to 60% and 56.7%, respectively. Consistently, significantly greater PO, CAT, and GSH-px activity and significantly lower MDA concentration in the vp19 and vp (19 + 28) groups compared to the control group. These results demonstrate that the trans-vp19 and trans-vp (19 + 28) gene of Syn7942 significantly facilitated the immune and antioxidant capacity of crayfish. Therefore, the trans-vp19 and trans-vp (19 + 28) genes of Syn7942 could provide protection for crayfish as an anti-WSSV oral medication.

Expression of miR-152 in cervical cancer and its influence on cisplatin resistance.

Background: Cervical cancer has a high mortality rate. Aim: We aimed to study the expression of micro ribonucleic acid 152 (miR-152) in cervical cancer and its influence on cisplatin (DDP) resistance. Methodology: Cervical cancer Hela cells were divided into control, DDP, DDP + mimic nc and DDP + miR-152 mimic groups. Results: DDP, DDP + mimic nc and DDP + miR-152 mimic groups had lower cell survival rate, smaller number of single clones and cells penetrating the membrane, and higher apoptosis rate and miR-152 expression than those of the control group (P<0.05). Compared with DDP and DDP + mimic nc groups, the cell survival rate, number of single clones and number of cells penetrating the membrane significantly decreased, while the apoptosis rate and miR-152 expression increased in the DDP + miR-152 mimic group (P<0.05). ERBB3 was a downstream target gene of miR-152. Hela cells transfected with miR-152 mimic had lower protein expressions of Snail, ERBB3, Akt2, p-Akt and c-myc than those of NC cells (P<0.05). Conclusion: MiR-152 suppresses the proliferation, migration and infiltration of cervical cancer cells and reduces their resistance to DDP chemotherapy by inhibiting the expressions of proteins in the ERBB3/Akt/c-myc and ERBB3/Akt/Snail pathways.

Do transition and hepatobiliary phase hypointensity improve LI-RADS categorization as an alternative washout: a systematic review and meta-analysis.

OBJECTIVE: The definition of washout in gadoxetate disodium-enhanced MRI (Gd-EOB-MRI) is controversial. The current Liver Imaging Reporting and Data System (LI-RADS) defines washout only in the portal venous phase on Gd-EOB-MRI, leading to low diagnostic sensitivity for HCC. We performed a meta-analysis to compare the diagnostic performance of Gd-EOB-MRI using conventional (cWO) and modified (mWO) definitions of washout. METHODS: The PubMed and EMBASE databases were searched to identify studies published between January 1, 2010, and August 1, 2021, that compared the diagnostic performance of cWO and mWO for HCC. The mWOs added transition phase (TP) hypointensity (mWO-1), hepatobiliary phase (HBP) hypointensity (mWO-2), or both (mWO-3). The pooled sensitivity and specificity were calculated using a bivariate random-effects model. Study heterogeneity was explored by subgroup analysis and meta-regression analysis. RESULTS: Ten comparative studies with 2391 patients were included. Compared to cWO, the overall mWO yielded significantly higher sensitivity (71% vs. 81%, p = 0.00) and lower specificity (97% vs. 93%, p = 0.01) for diagnosing HCC. The area under the curve (AUC) was 0.90 and 0.94 for the cWO and mWO, respectively. Regarding the three types of mWOs, mWO-2 showed the highest sensitivity (85%) and specificity (96%) for diagnosing HCC. mWO-2 achieved the highest AUC (0.97), followed by mWO-1 (0.90), and mWO-3 (0.89). Average reviewer experience and scanner field strength were significantly associated with study heterogeneity (p < 0.05). CONCLUSIONS: Inclusion of TP and HBP hypointensity in the definition of washout improved the sensitivity with slightly lower specificity for diagnosing HCC in LI-RADS. KEY POINTS: • Compared to the conventional definition of washout, studies using a modified definition had higher sensitivity (71% vs. 81%) but lower specificity (97% vs. 93%) in LI-RADS for the diagnosis of HCC. • Hepatobiliary phase hypointensity may be a preferred alternative washout for HCC diagnosis with the highest area under the curve. • Studies with experienced reviewer or 3.0T MRI showed higher sensitivity and lower specificity for diagnosing HCC when using modified washout (p < 0.05).

Vacuum Ultraviolet Photodissociation Branching Ratios of 12C16O, 13C16O, and 12C18O from 100500 to 102320 cm-1.

The C+ ion photofragment spectra and photodissociation branching ratios into the two energetically available channels, C(1D) + O(3P) and C(3P) + O(3P), have been obtained for the three CO isotopologues, 12C16O, 13C16O, and 12C18O, in the vacuum ultraviolet range 100500-102320 cm-1. The two vibronic states of 1Σ+ symmetry, F(3dσ) 1Σ+(υ' = 1) and J(4sσ) 1Σ+(υ' = 0), predominantly dissociate into the lowest channel C(3P) + O(3P) through interactions with the repulsive D'1Σ+ state. All three vibronic states of 1Π symmetry, E'1Π(υ' = 1, 2) and G(3dπ) 1Π(υ' = 0), dissociate into both of the channels above. The photodissociation branching ratios into the channel C(1D) + O(3P) for E'1Π(υ' = 1, 2) are found to be independent of both the rotational quantum number and e/f parity, while those for G(3dπ) 1Π(υ' = 0) strongly depend on the rotational quantum number, indicating very different predissociation pathways between the valence states E'1Π(υ' = 1, 2) and the Rydberg state G(3dπ) 1Π(υ' = 0). The potential energy curves of CO in the aforementioned energy range and below have recently been well constructed due to a series of interplays between high-resolution spectroscopic studies and theoretical calculations; the photodissociation branching ratios measured in this study can provide further benchmarks for future theoretical investigations which aim to understand the detailed predissociation dynamics of CO.

Reinvestigation of the Rydberg W1Π(ν = 1) level of 12C16O, 13C16O, and 12C18O through rotationally dependent photodissociation branching ratio measurements.

A recent high resolution photoabsorption study revealed that the Rydberg W1Π(ν = 1) level of carbon monoxide (CO) is perturbed by the valence E″1Π(ν = 0) level, and the predissociation linewidth shows drastic variation at the crossing point due to the interference effect [Heays et al., J. Chem. Phys. 141(14), 144311 (2014)]. Here, we reinvestigate the Rydberg W1Π(ν = 1) level for the three CO isotopologues, 12C16O, 13C16O, and 12C18O, by measuring the rotationally dependent photodissociation branching ratios. The C+ ion photofragment spectra obtained here reproduce the recent high resolution photoabsorption spectra very well, including the presence of the valence E″1Π(ν = 0) level. The photodissociation branching ratios into the spin-forbidden channel C(1D) + O(3P) show sudden increases at the crossing point between the W1Π(ν = 1) and E″1Π(ν = 0) levels, which is in perfect accordance with the drastic variation of the linewidth observed in the recent spectroscopic study. Further analysis reveals that the partial predissociation rate into the lowest channel C(3P) + O(3P) shows a much more prominent decrease at the crossing point, which is caused by the interference effect between the W1Π(ν = 1) and E″1Π(ν = 0) levels, than that into the spin-forbidden channel C(1D) + O(3P), and this is the reason of the sudden increase as observed in the photodissociation branching ratio measurements. We hope that the current experimental investigation will stimulate further theoretical studies, which could thoroughly address all the experimental observations in a quantitative way.

Channel-resolved rotationally dependent predissociation rate constants reveal the state-to-state dissociation dynamics of carbon monoxide in electronically excited states.

Rotational dependence of the total predissociation rate constants deduced from linewidth measurements in spectroscopic studies have often been used to predict the possible electronic coupling schemes in the photodissociation process of carbon monoxide (CO), while the intrinsic multi-channel characteristics of CO photodissociation make the prediction unreliable and sometimes misleading conclusions could be reached. Here, we demonstrate for the first time in the Rydberg 4p(2) and 5p(0) complexes region of 13C16O that absolute partial predissociation rate constants into each individual channel and their dependences on the rotational quantum numbers can be obtained through branching ratio measurements in combination with the total predissociation rate constants reported in spectroscopic studies. These channel-resolved rotationally dependent predissociation rate constants are found to unambiguously reveal the detailed state-to-state photodissociation dynamics of CO, which is not available from either the branching ratio or the total predissociation rate constant measurements individually.

Strong and selective isotope effect in the vacuum ultraviolet photodissociation branching ratios of carbon monoxide.

Rare isotope (13C, 17O and 18O) substitutions can substantially change absorption line positions, oscillator strengths and photodissociation rates of carbon monoxide (CO) in the vacuum ultraviolet (VUV) region, which has been well accounted for in recent photochemical models for understanding the large isotopic fractionation effects that are apparent in carbon and oxygen in the solar system and molecular clouds. Here, we demonstrate a strong isotope effect associated with the VUV photodissociation of CO by measuring the branching ratios of 12C16O and 13C16O in the Rydberg 4p(2), 5p(0) and 5s(0) complex region. The measurements show that the quantum yields of electronically excited C atoms in the photodissociation of 13C16O are dramatically different from those of 12C16O, revealing strong isotope effect. This isotope effect strongly depends on specific quantum states of CO being excited, which implies that such effect must be considered in the photochemical models on a state by state basis.

Rotational dependence of the branching ratios and fragment angular distributions for the photodissociation of 12C16O in the Rydberg 4p(2) and 5p(0) complex region (92.84-93.37 nm).

12C16O shows complicated absorption structures in the wavelength range of 92.84-93.37 nm caused by the mutual interactions among the Rydberg 4p(2) and 5p(0) complexes, and several diffuse valence states. Here, we systematically measured the branching ratios and fragment angular distributions for the photodissociation of 12C16O in the wavelength range using our mini-time-slice velocity-map imaging (mini-TSVMI) setup and a tunable vacuum ultraviolet (VUV) laser radiation source generated by the two-photon resonance-enhanced four-wave mixing scheme. Various patterns of rotational dependence for the photodissociation branching ratios have been observed for different vibronic states, and they are found to be consistent with previous spectroscopic investigations, revealing the complicated coupling schemes and predissociation dynamics in this region. Irregular angular distributions of the photofragments have been observed, especially in the Rydberg 5p(0) complex region. This has been attributed to the simultaneous excitation of multiple states with different symmetries in this region. The newly observed underlying continuum in the Rydberg 5p(0) complex region has been directly detected in the present study, and it is found to be of 1Σ+ symmetry and dissociates predominantly into the C(3P) + O(3P) channel. This study generally confirms the results of previous spectroscopic studies from a different perspective, and adds new knowledge for understanding the complicated predissociation dynamics of 12C16O in the titled wavelength range.

A mini-photofragment translational spectrometer with ion velocity map imaging using low voltage acceleration.

A mini time-sliced ion velocity map imaging photofragment translational spectrometer using low voltage acceleration has been constructed. The innovation of this apparatus adopts a relative low voltage (30-150 V) to substitute the traditional high voltage (650-4000 V) to accelerate and focus the fragment ions. The overall length of the flight path is merely 12 cm. There are many advantages for this instrument, such as compact structure, less interference, and easy to operate and control. Low voltage acceleration gives a longer turn-around time to the photofragment ions forming a thicker Newton sphere, which provides sufficient time for slicing. Ion trajectory simulation has been performed for determining the structure dimensions and the operating voltages. The photodissociation and multiphoton ionization of O2 at 224.999 nm is used to calibrate the ion images and examine the overall performance of the new spectrometer. The velocity resolution (Δν/ν) of this spectrometer from O2 photodissociation is about 0.8%, which is better than most previous results using high acceleration voltage. For the case of CF3I dissociation at 277.38 nm, many CF3 vibrational states have been resolved, and the anisotropy parameter has been measured. The application of low voltage acceleration has shown its advantages on the ion velocity map imaging (VMI) apparatus. The miniaturization of the VMI instruments can be realized on the premise of high resolution.

Conformational preferences and isomerization upon excitation/ionization of 2-methoxypyridine and 2-N-methylaminopyridine.

Conformers from the rotations of the methyl group and the methoxy or methylamino group, namely staggered (s)/eclipsed (e)-cis/trans 2-methoxypyridine (2MOP) and 2-N-methylaminopyridine (2NMP), are studied using theoretical calculations in combination with one-color resonance-enhanced two-photon ionization (1C-R2PI) and mass-analyzed threshold ionization (MATI) spectroscopies. The calculations predict that, for cis 2MOP, trans 2MOP and trans 2NMP, only the s conformers are stable in the S0, S1 and D0 states. However, for cis 2NMP, the stable conformer is staggered in the S0 state but eclipsed in the S1 and D0 states, indicating an isomerization upon the excitation or ionization from the S0 state. This is experimentally supported by the 1C-R2PI and MATI spectra of 2NMP. Due to the relative instability, the number density of trans 2MOP is too low in the sample to be detected. All the bands in the 1C-R2PI and MATI spectra of 2MOP are assigned to s-cis 2MOP. The energy differences between cis and trans conformers are derived from excitation and ionization energies, indicating another conformational isomerization: stable trans 2NMP in the S0 and S1 states but stable cis 2NMP in the D0 state. For 2MOP, the so-called syn preference previously found for the S0 state is also observed in the S1 and D0 states. The conformational preference and isomerization are discussed with natural bond orbital calculations and reduced density gradient analysis. For 2MOP, the syn preferences are mainly caused by the exchange repulsion among several σ-orbitals of the OCH3 group and the pyridine ring. While the relative stabilities of the s and e conformers of cis 2MOP and cis 2NMP are simultaneously influenced by steric repulsion and orbital interactions.