[A rational analysis of the commonly used renal tumor scoring systems in predicting surgical outcomes of cystic renal masses]

Objective: To explore the predictive effect of the renal tumor scoring system on the surgical outcomes of cystic renal masses (CRM). Methods: A retrospective analysis was performed on the data of 234 patients who received robotic-assisted partial nephrectomy (RAPN) treatment in the First Affiliated Hospital of Xi'an Jiaotong University from January 2018 to June 2020. And 31 cases had CRM and 203 cases had solid renal masses (SRM). The propensity score of patients was calculated by logistic regression model, and 1∶2 matching was performed by the nearest neighbor method. The changes in perioperative indexes and long-term estimated glomerular filtration rate (eGFR) in CRM group and SRM group were compared. The CRM group and SRM group were stratified according to the complexity grading of R.E.N.A.L. score and PADUA score, respectively, to compare the difference in the achievement rate of ideal surgical outcome between the two groups, and analyze the predictive factors affected. The CRM diameter was stratified with 4 cm as the cut-off value (CRM1 group with a diameter<4 cm, CRM2 group with a diameter≥4 cm), and the surgical results were compared with the matched SRM1 group and SRM2 group. Results: In the matching cohort, the CRM group comprised 29 patients with a mean age of (48.7±10.8) years, of which 22 (75.9%) were males. The SRM group included 58 patients with a mean age of (50.4±10.2) years, of which 41 (70.7%) were males, with no statistically significant difference (all P>0.05). The warm ischemia time (WIT) [M (Q1,Q3)] in the CRM group was longer than that in the SRM group [23(18, 25) vs 19(17, 25) min, P=0.040]. The operation time (OT) [M (Q1,Q3)] in the CRM group was also longer than that of the SRM group [130(100, 150) vs 108(86, 120) min, P=0.006]. The change in serum creatinine before and after the operation [M (Q1,Q3)] was higher in the CRM group than in the SRM group [15(10, 23) vs 12(6, 17) μmol/L, P=0.030]. The ideal surgical outcomes were achieved in 7 patients (24.1%) in the CRM group and 36 patients (62.1%) in the SRM group. The number of patients achieving ideal surgical outcomes in R.E.N.A.L. intermediate complex surgery and PADUA advanced complex surgery in the SRM group were 24 (58.5%) and 15 (51.7%), respectively, which were higher than those in the CRM group 6 (27.3%) and 1 (5.9%) respectively (P<0.05). Preoperative eGFR (OR=0.758, 95%CI: 0.719-0.799) and the nature of the tumor (CRM as reference, OR=4.883, 95%CI: 1.550-15.378) were influencing factors for achieving the ideal surgical outcome. Subgroup analysis showed that eGFR changes before and after surgery and the estimated blood loss (EBL) in the CRM2 group were higher than those in the SRM2 group, and WIT and OT were longer than those in the SRM2 group (all P<0.05). The EBL and WIT of the CRM1 group were shorter than those of the CRM2 group (P<0.05). Conclusion: The surgical risk of RAPN in complex CRMs with a maximum diameter of≥4 cm is higher than the risk of RAPN in SRM with equivalent R.E.N.A.L. and PADUA scores.

Corn stover harvest N and energy budgets in central Iowa

Harvesting corn stover removes N from the fields, but its effect on subsurface drainage and other N losses is uncertain. We used the Root Zone Water Quality Model (RZWQM) to examine N losses with 0 (NRR) or 50% (RR) corn residue removal within a corn and soybean rotation over a 10-yr period. In general, all simulations used the same pre-plant or post-emergence N fertilizer rate (200 kg ha^-1 yr^-1). Simulated annual corn yields averaged 10.7 Mg ha^-1 for the post emergence applications (NRRpost and RRpost), and 9.5 and 9.4 Mg ha^-1 yr^-1 for NRRpre and RRpre. Average total N input during corn years was 19.3 kg N ha^-1 greater for NRRpre compared to RRpre due to additional N in surface residues, but drainage N loss was only 1.1 kg N ha^-1 yr^-1 greater for NRRpre. Post-emergence N application with no residue removal (NRRpost) reduced average drainage N loss by 16.5 kg ha^-1 yr^-1 compared to pre-plant N fertilization (NRRpre). The farm-gate net energy ratio was greatest for RRpost and lowest for NRRpre (14.1 and 10.4 MJ output per MJ input) while greenhouse gas intensity was lowest for RRpost and highest for NRRpre (11.7 and 17.3 g CO₂-eq. MJ^-1 output). Similar to published studies, the simulations showed little difference in N₂O emissions between scenarios, decreased microbial immobilization for RR compared to NRR, and small soil carbon changes over the 10-yr simulation. In contrast to several previous modeling studies, the crop yield and N lost to drain flow were nearly the same between NRR and RR without supplemental N applied to replace N removed with corn stover. These results are important to optimizing the energy and nitrogen budgets associated with corn stover harvest and for developing a sustainable bioenergy industry.

N loss to drain flow and N2O emissions from a corn-soybean rotation with winter rye

Anthropogenic perturbation of the global nitrogen cycle and its effects on the environment such as hypoxia in coastal regions and increased N₂O emissions is of increasing, multi-disciplinary, worldwide concern, and agricultural production is a major contributor. Only limited studies, however, have simultaneously investigated NO₃^- losses to subsurface drain flow and N₂O emissions under corn-soybean production. We used the Root Zone Water Quality Model (RZWQM) to evaluate NO₃^- losses to drain flow and N₂O emissions in a corn-soybean system with a winter rye cover crop (CC) in central Iowa over a nine year period. The observed and simulated average drain flow N concentration reductions from CC were 60% and 54% compared to the no cover crop system (NCC). Average annual April through October cumulative observed and simulated N₂O emissions (2004-2010) were 6.7 and 6.0kgN₂O-Nha^-1yr^-1 for NCC, and 6.2 and 7.2kgNha^-1 for CC. In contrast to previous research, monthly N₂O emissions were generally greatest when N loss to leaching were greatest, mostly because relatively high rainfall occurred during the months fertilizer was applied. N₂O emission factors of 0.032 and 0.041 were estimated for NCC and CC using the tested model, which are similar to field results in the region. A local sensitivity analysis suggests that lower soil field capacity affects RZWQM simulations, which includes increased drain flow nitrate concentrations, increased N mineralization, and reduced soil water content. The results suggest that 1) RZWQM is a promising tool to estimate N₂O emissions from subsurface drained corn-soybean rotations and to estimate the relative effects of a winter rye cover crop over a nine year period on nitrate loss to drain flow and 2) soil field capacity is an important parameter to model N mineralization and N loss to drain flow.

Quantifying climate and management effects on regional crop yield and nitrogen leaching in the north china plain

Better water and nitrogen (N) management requires better understanding of soil water and N balances and their effects on crop yield under various climate and soil conditions. In this study, the calibrated Root Zone Water Quality Model (RZWQM2) was used to assess crop yield and N leaching under current and alternative management practices in a double-cropped wheat ( L.) and maize ( L.) system under long-term weather conditions (1970-2009) for dominant soil types at 15 locations in the North China Plain. The results provided quantitative long-term variation of deep seepage and N leaching at these locations, which strengthened the existing qualitative knowledge for site-specific management of water and N. In general, the current management practices showed high residual soil N and N leaching in the region, with the amounts varying between crops and from location to location and from year to year. Seasonal rainfall explained 39 to 84% of the variability in N leaching (1970-2009) in maize across locations, while for wheat, its relationship with N leaching was significant ( < 0.01) only at five locations. When N and/or irrigation inputs were reduced to 40 to 80% of their current levels, N leaching generally responded more to N rate than to irrigation, while the reverse was true for crop yield at most locations. Matching N input with crop requirements under limited water conditions helped achieve lower N leaching without considerable soil N accumulation. Based on the long-term simulation results and water resources availability in the region, it is recommended to irrigate at 60 to 80% of the current water levels and fertilize only at 40 to 60% of the current N rate to minimizing N leaching without compromising crop yield.

Development of pattern ERG and pattern VEP spatial resolution in kittens with unilateral esotropia

PURPOSE

To follow the development of strabismic amblyopia longitudinally by comparing mean amplitudes and the visual spatial resolving ability of retinal and cortical pattern responses at various stages of postnatal development in unilateral iatrogenic convergent strabismic kittens.

METHODS

Surgery to produce iatrogenic convergent strabismus was performed on 20 kittens at 3 weeks of age; three kittens were used for controls. The monocular transient pattern electroretinogram (PERG) and pattern visual evoked potential (PVEP) were recorded simultaneously on the 23 kittens throughout development.

RESULTS

The PVEPs of the strabismic eyes were very reduced at 4 to 5 postnatal weeks (P < 0.01). The reduction increased at 6 to 16 weeks but was even worse at 17 to 30 weeks. The PERG of the squinting eye showed only a slight reduction in the first 4 to 5 weeks of age (P > 0.05), the decrease of responses was significant (P < 0.01) at 6 to 16 weeks and 17 to 30 weeks. At 4 to 8 weeks of age, the PVEP evoked through the unoperated eye in kittens consisted mainly of two positive components of similar amplitude. During development, the slow component decreased in comparison to the fast one, and its peak shifted forward until it merged into the fast (P100) component.

CONCLUSIONS

Esotropic amblyopia did affect the PERG and the PVEP in the amblyopic eye, but the effect on the PERG was less severe, had slower onset, and did not continue as long as for the PVEP.