We consider the problem of estimating the L1 distance between two discrete probability measures P and Q from empirical data in a nonasymptotic and large alphabet setting. When Q is known and one ...obtains n samples from P, we show that for every Q, the minimax rate-optimal estimator with n samples achieves performance comparable to that of the maximum likelihood estimator with n ln n samples. When both P and Q are unknown, we construct minimax rate-optimal estimators, whose worst case performance is essentially that of the known Q case with Q being uniform, implying that Q being uniform is essentially the most difficult case. The effective sample size enlargement phenomenon, identified by Jiao et al., holds both in the known Q case for every Q and the Q unknown case. However, the construction of optimal estimators for ∥P - Q∥1 requires new techniques and insights beyond the approximation-based method of functional estimation by Jiao et al.
Early outcomes of the Y-incision technique to enlarge the aortic annulus 3 to 4 valve sizes Yang, Bo; Ghita, Corina; Makkinejad, Alexander ...
Journal of thoracic and cardiovascular surgery/The Journal of thoracic and cardiovascular surgery/The journal of thoracic and cardiovascular surgery,
April 2024, 2024-Apr, 2024-04-00, 20240401, Volume:
167, Issue:
4
Journal Article
Peer reviewed
Open access
To evaluate the safety and efficacy of a novel aortic annular enlargement technique.
From August 2020 to February 2022, 50 consecutive cases of aortic valve replacement with Y-incision aortic annular ...enlargement and other combined cardiac procedures were performed primarily for severe aortic stenosis. Data were obtained through medical record review, The Society of Thoracic Surgeons database, and National Death Index data.
The median age was 65 (59, 71) years, 70% of patients were female, and 26% had previous cardiac surgery. Sixty-six percent patients had isolated aortic valve replacement. The preoperative mean gradient was 40 (30, 47) mm Hg, and the native aortic annular size was 21 (19, 23) mm. After aortic annular enlargement, the median prosthesis size was 27 (27, 29) with 54% of patients having a size 29 or the largest sized valve. The median increment of annulus enlargement was 3 (3, 4) valve sizes. 88% of patients received no blood transfusion. There were no major postoperative complications, including operative mortality, renal failure requiring permanent dialysis, mediastinitis, or reoperation for bleeding, except for 1 stroke. Three-month postoperative computed tomography aortogram showed the aortic root was enlarged from 27 (24, 30) to 40 (36, 41) mm without aortic pseudoaneurysm. The postoperative mean gradient was 7 (5, 8) mm Hg and valve area was 1.9 (1.7, 2.3) cm2 at 3 to 12 months. Mitral and tricuspid valve functions were significantly improved. Survival was 100% at 18 months.
Y-incision aortic annular enlargement was safe and effective for upsizing the aortic annulus by 3 to 4 valve sizes.
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Purpose: Axial Elongation in myopic eyes may be caused by growth of Bruch's membrane along the equator of the eye. This may lead to a change in the eye morphology and may put pressure on the retinal ...pigment epithelium (RPE) and on BM at the posterior pole of the eye. To relieve the pressure congregating on the posterior pole, an increase in Bruch's membrane opening (BMO) and laquer cracks (LCs) may form. The BMO may develop an enlargement of the parapillary gamma zone (PGZ) defined as a parapapillary region free of BM. Previous studies concluded that an enlargement of PGZ correlates with less disruptions of BM or RPE as in LCs or macular BM defects at the posterior pole. This case series examines three individuals with highly myopic eyes during a 10‐year follow‐up with disappearances of LCs.
Methods: Funduscopy and OCT imaging were used to determine LC occurrence and change in a 10‐year follow‐up study.
Results: The patients were examined in 2001 and 2011. The age of the patients was at the initial exam 45, 63 and 69 years. The axial length was 23.17 and 27.66 mm. The refractive error was between −7.38 diopters and − 17.13dpt. The patients showed initially in 2001 a LC and a vertically oval optic disc head. After re‐examination in 2011 the LC was not visible in funduscopy or optical coherence tomography.
Conclusions: The findings suggest that LCs can decrease in width and severity.
It is uncommon to use the grid network for extracting the building boundaries from building points, which is due to the effect of grid points on the outline accuracy. In this paper, a novel method is ...proposed for extracting the building outline from gridded building points. Accordingly, a grid is generated, and the boundary points are extracted. These points are traced based on a new topologically aware propagation algorithm. The initial principal directions are estimated first by using multiple points. Afterward, the initial outline is obtained. Next, the major part of our methodology starts with outline enlargement, which depends on the outline corners' propagation. The value and direction of the enlargement for each line are determined separately to generate an enlarged outline. The results show the high efficiency of the enlargement method, which improves the accuracy by up to 70%. The proposed method can achieve high pixel-based correctness of 99%.
•Eliminating the effect of using the grid points in extracting the building boundary.•The enlargement method is automatic and parameter-free.•The accuracy of the outlines is not related to the resolution of the grid network.•Extraction of the principal directions by using multiple neighborhoods.
An efficient cascade reaction of tryptamine‐derived isocyanides with C,N‐cyclic azomethine imines is described. The polycyclic pyrrolo2,3‐cquinoline derivatives, which benefited from rearrangement ...process driven by hydrogen bonding, could be directly assembled in moderate to good yields (40–87 %) under metal‐free and mild conditions. This transformation involved four new heterocyclic rings formations and uniquely, ring opening of indole as well as ring expansion of C,N‐cyclic azomethine imine. Both experimental and DFT studies provided guidance on the in‐depth insight into the reaction pathways and hydrogen bonding was identified to lower the free energy barrier in transition states. This work constitutes a rare example of tryptamine‐derived isocyanide‐based cascade reactions, and potentially could be a powerful synthetic strategy for accessing polycyclic analogues involved in natural products.
Natural‐product‐like polycyclic pyrrolo2,3‐cquinoline derivatives have been easily constructed in one‐step process from easily available starting materials. This reaction involves two ring enlargements and four heterocyclic ring formations via cascade rearrangement process. DFT studies reveal the crucial hydrogen‐bonding interaction in the detailed mechanistic investigation.
Objectives
Amygdala enlargement is detected on magnetic resonance imaging (MRI) in some patients with drug‐resistant temporal lobe epilepsy (TLE), but its clinical significance remains uncertain We ...aimed to assess if the presence of amygdala enlargement (1) predicted seizure outcome following anterior temporal lobectomy with amygdalohippocampectomy (ATL‐AH) and (2) was associated with specific histopathological changes.
Methods
This was a case–control study. We included patients with drug‐resistant TLE who underwent ATL‐AH with and without amygdala enlargement detected on pre‐operative MRI. Amygdala volumetry was done using FreeSurfer for patients who had high‐resolution T1‐weighted images. Mann–Whitney U test was used to compare pre‐operative clinical characteristics between the two groups. The amygdala volume on the epileptogenic side was compared to the amygdala volume on the contralateral side among cases and controls. Then, we used a two‐sample, independent t test to compare the means of amygdala volume differences between cases and controls. The chi‐square test was used to assess the correlation of amygdala enlargement with (1) post‐surgical seizure outcomes and (2) histopathological changes.
Results
Nineteen patients with and 19 patients without amygdala enlargement were studied. Their median age at surgery was 38 years for cases and 39 years for controls, and 52.6% were male. There were no statistically significant differences between the two groups in their pre‐operative clinical characteristics. There were significant differences in the means of volume difference between cases and controls (Diff = 457.2 mm3, 95% confidence interval CI 289.6–624.8; p < .001) and in the means of percentage difference (p < .001). However, there was no significant association between amygdala enlargement and surgical outcome (p = .72) or histopathological changes (p = .63).
Significance
The presence of amygdala enlargement on the pre‐operative brain MRI in patients with TLE does not affect the surgical outcome following ATL‐AH, and it does not necessarily suggest abnormal histopathology. These findings suggest that amygdala enlargement might reflect a secondary reactive process to seizures in the epileptogenic temporal lobe.
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•Particle size evolution due to vapor heterogeneous condensation is modelled.•Heterogeneous nucleation theory and condensation droplet growth theory are applied.•Effects of key ...operational parameters on particle size enlargement are evaluated.•Condensation growth of particles at typical contact angles are compared.•Model predictions of particle size distribution match well with experimental data.
Vapor heterogeneous condensation with PM2.5 as nuclei is a promising approach to enlarge the particle sizes and thus facilitate subsequent particulate abatement by the existing inertial separators. However, the investigation on PM2.5 size enlargement by vapor heterogeneous condensation, which is important to optimize the particulate abatement process, has been largely lacking. In this study, the evolution of particle size distribution due to vapor heterogeneous condensation on the surfaces of polydisperse insoluble PM2.5 was modelled based on the classical heterogeneous nucleation theory and the condensation droplet growth theory. Using this model, the effects of operational parameters on the particle size distribution after heterogeneous condensation were numerically investigated. The results show that the polydisperse fine particles shift to monodisperse coarse particles at a small contact angle, whereas bimodal particle size distribution after heterogeneous condensation is generated at a large contact angle. Higher vapor saturation ratio, higher gas temperature, longer residence time, and greater geometric mean particle size are beneficial to PM2.5 size enlargement and subsequent particulate abatement. Moreover, the geometric standard deviation of particle sizes has little effect on the PM2.5 size enlargement. The model predictions of the particle size distribution after vapor heterogeneous condensation match well with the experimental data.
Background
Prospective trials of active surveillance (AS) have shown low rates of progression in low-risk papillary thyroid microcarcinoma (PTMC; T1aN0M0). However, the significance of multifocality ...as a prognostic factor remains controversial.
Methods
Data from 571 patients (mean age, 53.1 years; 495 females) who underwent AS were reviewed. PTMC was unifocal in 457 patients (80.0%) and multifocal in 114 patients (20.0%), with 2–5 lesions each (261 tumors in total). Tumor progression was defined as tumor size enlargement ≥ 3 mm and/or development of clinically evident lymph node metastasis (LNM).
Results
After a mean duration of AS of 7.6 years, 53 patients (9.3%) showed tumor enlargement and 8 patients (1.4%) developed LNM. The 10-year progression rate was 13.1%. Age, sex, and calcification pattern did not differ significantly between uni- and multifocal diseases. However, anti-thyroglobulin antibody and/or anti-thyroid peroxidase antibody was more frequently positive with multifocal PTMCs (46.7%) than with unifocal disease (34.4%,
p =
0.024). Patients with uni- and multifocal disease showed no significant differences in 10-year rate of tumor enlargement (11.4% vs. 14.8%), LNM development (1.1% vs. 2.4%), or progression (12.4% vs 15.9%). Multivariate analysis of predictors for progression showed multifocality was not a significant risk factor (odds ratio, 1.45; 95% confidence interval, 0.79–2.54;
p =
0.22). Eventually, 9 patients (7.9%) with multifocal PTMCs underwent surgery and 7 needed total thyroidectomy, although 7 still showed T1N0M0 low-risk cancer.
Conclusions
Even patients with multiple PTMCs (T1amN0M0) are good candidates for AS. Many patients can avoid total thyroidectomy and subsequent surgical complications.
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