From dS to AdS and back

We describe in more detail the general relation uncovered in our previous work between boundary correlators in de Sitter (dS) and in Euclidean anti-de Sitter (EAdS) space, at any order in perturbation theory. Assuming the Bunch-Davies vacuum at early times, any given diagram contributing to a boundary correlator in dS can be expressed as a linear combination of Witten diagrams for the corresponding process in EAdS, where the relative coefficients are fixed by consistent on-shell factorisation in dS. These coefficients are given by certain sinusoidal factors which account for the change in coefficient of the contact sub-diagrams from EAdS to dS, which we argue encode (perturbative) unitary time evolution in dS. dS boundary correlators with Bunch-Davies initial conditions thus perturbatively have the same singularity structure as their Euclidean AdS counterparts and the identities between them allow to directly import the wealth of techniques, results and understanding from AdS to dS. This includes the Conformal Partial Wave expansion and, by going from single-valued Witten diagrams in EAdS to Lorentzian AdS, the Froissart-Gribov inversion formula. We give a few (among the many possible) applications both at tree and loop level. Such identities between boundary correlators in dS and EAdS are made manifest by the Mellin-Barnes representation of boundary correlators, which we point out is a useful tool in its own right as the analogue of the Fourier transform for the dilatation group. The Mellin-Barnes representation in particular makes manifest factorisation and dispersion formulas for bulk-to-bulk propagators in (EA)dS, which imply Cutkosky cutting rules and dispersion formulas for boundary correlators in (EA)dS. Our results are completely general and in particular apply to any interaction of (integer) spinning fields.

One-shot dilation versus metallic dilation technique for access in percutaneous nephrolithotomy: comparison of efficacy, access time and fluoroscopic time

Objective: The aim of this study was to compare the efficacy, access tract dilation time and fluoroscopic time between the one-shot dilation technique and telescopic metal dilatation technique in patients undergoing percutaneous nephrolithotomy in Nakornping Hospital. Materials and Methods: Sixty-six patients who underwent percutaneous nephrolithotomy from January 2020 to July 2021 were included in the study and they were randomly divided into two groups. In group 1 (32 patients), telescopic metal dilation was used, in group 2 (33 patients), the one-shot technique was used. Success rates of dilation, access tract dilation time and fluoroscopic time were evaluated. Results: The success rate of dilation was 100% in both groups. The access tract dilation time was 835.63 ± 309.68 seconds in group 1 and 569.42 ± 314.75 seconds in group 2 (p = 0.001). The fluoroscopic time was 48.16 ± 22.16 seconds in group 1 and 41.97 ± 23.99 seconds in group 2 (p = 0.29). The access tract dilation time of the one-shot dilation technique was statistically significantly shorter than that in the telescopic metal dilatation group. The mean fluoroscopic time of the one- shot dilation technique was shorter than in telescopic metal dilatation but was not statistically significant. Conclusion: One-shot dilation technique is as effective as telescopic metal dilatation, with a significant reduction in access tract dilation time.

Clinical Characteristics of Choledochal Cysts With Intrahepatic Bile Duct Dilatations

Background: Whether the dilated intrahepatic bile duct (IHBD) has any effect on prognosis of choledochal cyst (CC) remains controversy. In the study, we aim to summarize the clinical characteristics and prognosis of those patients.Methods: A total of 192 children (47 males, 145 females) diagnosed with CC were identified in our hospital, including 127 without IHBD dilatation (group A) and 65 with IHBD dilatation (group B). A retrospective analysis was performed to explore the clinical characteristics of group B based on clinical indices, symptoms, and complications. Results: Compared with group A, incidences of jaundice and fever were significantly increased in group B (p=0.01 and 0.033, respectively). Preoperative total bilirubin (TB), direct bilirubin (DB), and indirect bilirubin (IDB) were also higher in group B than in group A (p=0.0052, 0.0005, and 0.0136, respectively), as were preoperative levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), and total bile acid (TBA) (p=0.0057, 0.0250, 0.0002, and 0.0242, respectively). Early postoperative GGT levels in group B remained abnormal and were significantly higher than in group A (p=0.0003). The risk of liver fibrosis or cirrhosis was significantly increased for group B compared with group A (p=0.012) and also occurred earlier in group B (p<0.001), among them, dilated IHBDs recovered to normal in 89.23% (7/65) of patients. Meanwhile, the incidence of postoperative pancreatitis increased significantly in group B as well (p=0.003).Conclusion: CC with IHBD dilatation was associated with significantly increased preoperative bilirubin levels, abnormal liver function, and higher incidence of liver fibrosis or cirrhosis early in the disease course. Timely radical surgery is recommended for such patients and postoperative extinction of the IHBD dilatation occurs early in most of those patients.

The timing of oesophageal dilatations in anastomotic stenosis after one-stage anastomosis for congenital oesophageal atresia

Background In infants with congenital oesophageal atresia, anastomotic stenosis easily occurs after one-stage oesophageal anastomosis, leading to dysphagia. In severe cases, oesophageal dilatation is required. In this paper, the timing of oesophageal dilatation in infants with anastomotic stenosis was investigated through retrospective data analysis. Methods The clinical data of 107 infants with oesophageal atresia who underwent one-stage anastomosis in our hospital from January 2015 to December 2018 were retrospectively analysed. Data such as the timing and frequency of oesophageal dilatation under gastroscopy after surgery were collected to analyse the timing of oesophageal dilatation in infants with different risk factors. Results For infants with refractory stenosis, the average number of dilatations in the early dilatation group (the first dilatation was performed within 6 months after the surgery) was 5.75 ± 0.5, which was higher than the average of 7.40 ± 1.35 times in the normal dilatation group (the first dilatation was performed 6 months after the surgery), P = 0.038. For the infants with anastomotic fistula and anastomotic stenosis, the number of oesophageal dilatations in the early dilatation group was 2.58 ± 2.02 times, which was less than the 6.38 ± 2.06 times in the normal dilatation group, P = 0.001. For infants with non-anastomotic fistula stenosis, early oesophageal dilatation could not reduce the total number of oesophageal dilatations. Conclusion Starting to perform oesophageal dilatation within 6 months after one-stage anastomosis for congenital oesophageal atresia can reduce the required number of dilatations in infants with postoperative anastomotic fistula and refractory anastomotic stenosis.

Balloon angioplasty: A promising adjunct to arteriovenous fistula creation compared with hydrostatic dilatation in small-caliber cephalic veins

Background To maintain the patency and longevity of arteriovenous fistula, the availability of a venous segment with adequate diameter is important. In Indian population, many chronic kidney disease patients have poor caliber veins. The study aimed to evaluate the efficacy of hydrostatic dilatation versus Primary balloon angioplasty of small caliber cephalic veins of (≤2.5 mm) preoperatively in terms of patency rate and maturation time of arteriovenous fistula. Methods Patients ( n = 80) with an end-stage renal disease requiring arteriovenous access surgery for hemodialysis with small caliber cephalic veins were randomized into two groups, i.e., hydrostatic dilatation and primary balloon angioplasty, each with 40 patients. All patients underwent a thorough clinical examination as well as duplex ultrasound vein mapping of both upper extremities. Patients were followed up for six months and primary patency, maturation time, and complications were noted. Results Immediate technical success with good palpable thrill was achieved in 97.5% of patients in the primary balloon angioplasty group and 87.5% in the hydrostatic dilatation group. The fistula maturation time in the primary balloon angioplasty group was 34.41 days and 46.18 days in the hydrostatic dilatation group. In the primary balloon angioplasty group, the primary patency of the fistula was 97.5% and 87.5% in the hydrostatic dilatation group, at six months. The arteriovenous fistula functioning rate was 77.5% in the hydrostatic dilatation group as compared to 92.5% in the primary balloon angioplasty group at six months. The incidence of surgical site infection was 5% in the primary balloon angioplasty group as compared to 10% in the hydrostatic dilatation group. Conclusion Primary balloon angioplasty of small caliber cephalic veins (≤2.5 mm) performed prior to arteriovenous fistula creation for hemodialysis is a beneficial procedure.

Aortic root aortopathy in bicuspid aortic valve associated with high genetic risk

Background The bicuspid aortic valve (BAV) is prone to ascending aortic dilatation (AAD) involving both the tubular segment and the aortic root. The genetic factor was proposed as one of the most important mechanisms for AAD. We hypothesized that the rare genetic variants mainly contribute to the pathogenesis of aortic roots in affected individuals. Methods The diameter of aortic root or ascending aorta ≥ 40 mm was counted as AAD. The targeted next-generation sequencing of 13 BAV-associated genes were performed on a continuous cohort of 96 unrelated BAV patients. The rare variants with allele frequency < 0.05% were selected and analyzed. Variants frequency was compared against the Exome aggregation consortium database. The pathogenicity of the genetic variants was evaluated according to the American College of Medical Genetics and Genomics guidelines. Results A total of 27 rare nonsynonymous coding variants involving 9 genes were identified in 25 individuals. The burden analysis revealed that variants in GATA5, GATA6, and NOTCH1 were significantly associated with BAV. Eighty percent of the pathogenic variants were detected in root group. The detection rate of rare variants was higher in root dilatation group (71.4%) compared with normal aorta (29.0%) and tubular dilatation groups (29.6%) (P = 0.018). The rare variant was identified as the independent risk factor of root dilatation [P = 0.014, hazard ratio = 23.9, 95% confidence interval (1.9–302.9)]. Conclusions Our results presented a broad genetic spectrum in BAV patients. The rare variants of BAV genes contribute the most to the root phenotype among BAV patients.

Nilpotent symmetries as a mechanism for Grand Unification

In the classic Coleman-Mandula no-go theorem which prohibits the unification of internal and spacetime symmetries, the assumption of the existence of a positive definite invariant scalar product on the Lie algebra of the internal group is essential. If one instead allows the scalar product to be positive semi-definite, this opens new possibilities for unification of gauge and spacetime symmetries. It follows from theorems on the structure of Lie algebras, that in the case of unified symmetries, the degenerate directions of the positive semi-definite invariant scalar product have to correspond to local symmetries with nilpotent generators. In this paper we construct a workable minimal toy model making use of this mechanism: it admits unified local symmetries having a compact (U(1)) component, a Lorentz (SL(2, ℂ)) component, and a nilpotent component gluing these together. The construction is such that the full unified symmetry group acts locally and faithfully on the matter field sector, whereas the gauge fields which would correspond to the nilpotent generators can be transformed out from the theory, leaving gauge fields only with compact charges. It is shown that already the ordinary Dirac equation admits an extremely simple prototype example for the above gauge field elimination mechanism: it has a local symmetry with corresponding eliminable gauge field, related to the dilatation group. The outlined symmetry unification mechanism can be used to by-pass the Coleman-Mandula and related no-go theorems in a way that is fundamentally different from supersymmetry. In particular, the mechanism avoids invocation of super-coordinates or extra dimensions for the underlying spacetime manifold.

The Timing of Oesophageal Dilatations in Anastomotic Stenosis After One-Stage Anastomosis for Congenital Oesophageal Atresia

Background: In infants with congenital oesophageal atresia, anastomotic stenosis easily occurs after one-stage oesophageal anastomosis, leading to dysphagia. In severe cases, oesophageal dilatation is required. In this paper, the timing of oesophageal dilatation in infants with anastomotic stenosis was investigated through retrospective data analysis.Methods: The clinical data of 107 infants with oesophageal atresia who underwent one-stage anastomosis in our hospital from January 2015 to December 2018 were retrospectively analysed. Data such as the timing and frequency of oesophageal dilatation under gastroscopy after surgery were collected to analyse the timing of oesophageal dilatation in infants with different risk factors.Results: For infants with refractory stenosis, the average number of dilatations in the early dilatation group (the first dilatation was performed within 6 months after the surgery) was 5.75±0.5, which was higher than the average of 7.40±1.35 times in the normal dilatation group (the first dilatation was performed 6 months after the surgery), P=0.038. For the infants with anastomotic fistula and anastomotic stenosis, the number of oesophageal dilatations in the early dilatation group was 2.58±2.02 times, which was less than the 6.38±2.06 times in the normal dilatation group, P=0.001. For infants with non-anastomotic fistula stenosis, early oesophageal dilatation could not reduce the total number of oesophageal dilatations.Conclusion: Starting to perform oesophageal dilatation within 6 months after one-stage anastomosis for congenital oesophageal atresia can reduce the required number of dilatations in infants with postoperative anastomotic fistula and refractory anastomotic stenosis.

Free margin length and geometric height in aortic root dilatation and leaflet prolapse: implications for aortic valve repair surgery

OBJECTIVES Our goal was to assess the aortic leaflet free margin length (FML) and geometric height (gH) in a normal aortic valve (AV), aorta dilatation and aortic leaflet prolapse. METHODS We measured the FML and gH intraoperatively in 132 patients operated on for aortic insufficiency, aortic dilatation, endocarditis or fibroelastoma. Patients were divided into 3 groups: normal tricuspid AV (group 1, n = 12), aortic dilatation (group 2, tricuspid = 43, bicuspid = 18) and leaflet prolapse (group 3, tricuspid = 32, bicuspid = 27). The FML and gH were compared between the groups and between the leaflets within each group. RESULTS In a normal tricuspid AV, the mean FML and gH were 34.7 ± 3.1 mm and 18.8 ± 1.7 mm, respectively. In group 2 tricuspid, the FML and gH were greater than those in group 1 (FML 43.7 ± 4.4, P &lt; 0.001; gH 21.2 ± 1.8, P = 0.003). In group 3, tricuspid, the FML of the prolapsing leaflet was greater than the FML of the non-prolapsing leaflet (48.3 ± 5.4 vs 42.2 ± 3.6; P &lt; 0.001). In group 2, bicuspid, FML of both leaflets were similar in group 2, but augmented on the fused leaflet compared to the non-fused leaflet in group 3 (fused 55.4 ± 6.3; non-fused 46.2 ± 6.2; P &lt; 0.001). In groups 2 and 3 bicuspid, the gH of the non-fused leaflet was systematically greater than the fused leaflet (group 2 non-fused 24.6 ± 2.5 vs fused 20.4 ± 2.1; P &lt; 0.001) CONCLUSIONS In aortic dilatation and leaflet prolapse, FML and, to a lesser extent, gH increased significantly compared to those of normal AV function. FML and gH dimensions also depended on the valve configuration (tricuspid/bicuspid). These data provide new insight into the pathomorphology of AV disease and will serve to further develop new methods of AV repair based on intraoperative measurements of the FML.

Outcome of Mode of Delivery in Nulliparous and Multiparous Women Presenting with Early and Late Cervical Dilatation

Background: Knowledge of the patterns of normal and abnormal labour, and of women’s behavior, is fundamental to the formulation of mode of delivery. It is observed that women admitted to hospital early have a higher frequency of obstetric interventions in labour than those admitted later. Objective: To study the outcome of spontaneous onset of labour in nulliparous and multiparous patients. Materials and method: During the study period of 1st July 2008 to 31st Dec 2008, 568 pregnant women admitted in Kumudini Women’s Medical College were included in this study. Mothers were observed since admission with spontaneous onset of labour and followed up till they were released from the hospital. Labour outcome was measured and mode of delivery was compared among nulliparous and multiparous women. Results: Among the nulliparous women, normal vaginal delivery occurred in 71 (23%) patients presented with early cervical dilatation (0-3 cm) and in 142 (46%) patients presented with late cervical dilatation (>4 cm). In nulliparous women caesarean section were needed in 60 (45.8%) patients in early cervical dilatation group and in 35 (19.8%) patients in late cervical dilatation group. In multiparous women, normal vaginal delivery occurred in 66 (25%) patients presented with early cervical dilatation and in 133 (51%) patients presented with late cervical dilatation whereas cesarean section were done in 35 (34.7%) patients and in 25 (15.8%) patients in the two groups respectively. Duration of labour between nulliparous and multiparous was significantly different (8 hours vs. 6 hours). Indication of caesarean section were, 61 (40%) patients due to prolong labour, 48 (34%) due to foetal distress and 44 (26%) due to cephalopelvic disproportion. Conclusion: Normal vaginal delivery occurred more and duration of labour was shorter in patients admitted with advanced labour (cervical dilatation >4cm). Delta Med Col J. Jan 2019 7(1): 16-20