Gauge-Theoretic Origin of Rydberg Quantum Spin Liquids

Recent atomic physics experiments and numerical works have reported complementary signatures of the emergence of a topological quantum spin liquid in models with blockade interactions. However, the specific mechanism stabilizing such a phase remains unclear. Here, we introduce an exact relation between an Ising-Higgs lattice gauge theory on the kagome lattice and blockaded models on Ruby lattices. This relation elucidates the origin of previously observed topological spin liquids by directly linking the latter to a deconfined phase of a solvable gauge theory. By means of exact diagonalization and unbiased quantum Monte Carlo simulations, we show that the deconfined phases extend in a broad region of the parameter space; these states are characterized by a large ground state overlap with resonating valence bond wave functions. These blockaded models include both creation or annihilation and hopping dynamics, and can be experimentally realized with Rydberg-dressed atoms, offering novel and controllable platforms for the engineering and characterization of spin liquid states.

Congenital giant megaureter: first neonatal case

The authors report the first neonatal presentation of a congenital giant megaureter (CGM), a very rare unilateral urinary anomaly, which is defined as "a ureter whose lumen is congenitally, focally and segmentally dilated to more than 10 times the normal diameter, in presence of normal bladder volume and function." The definition of CGM is purely descriptive; it can be secondary to several different diseases, and in the series of 21 CGM (12 in duplex system) reported by Chen-Ju Huang, the morphology of the distal ureter varied from a near normal caliber to a ureteral stenosis, a ureterocele or a complete ureteral atresia. J Pediatr Surg 36:944-945.

[Carcinoid of the appendix. Clinical report of 3 cases and diagnostic and therapeutic considerations]

The Authors report three cases of carcinoid of the appendix and discuss the difficult preoperative diagnosis and the different therapeutic options available. Over the period from January 1994 to December 1999, in the Surgery Unit of Penne Hospital, 424 appendicectomies were performed in 182 males and 242 females (age: 12-86 years; mean age: 39.9 years). In three cases the histological response was positive for carcinoid of the appendix. No postoperative mortality or morbility were reported. The authors analyze the biological peculiarities and the prognostic factors associated with appendiceal carcinoid tumours, such as tumour size and the lymphatic or vascular infiltration of the mesoappendix (and the corresponding more aggressive surgical treatments) and recommend an appropriate postoperative follow-up since synchronous or metachronous bowel carcinomas are likely to occur. Pharmacological therapy has also made important progress, with the possibility of administering compounds capable of interfering with tumour development and neoplastic growth.

[Use of hydrogen peroxide to neutralize formalin vapors during tissue sampling]

The problem of formaldehyde exhalation during tissue sampling for histological examinations is deeply felt in each histological laboratory. Most of adoptable methods which are used for the safeguard of operators' health can't frequently avoid situations where formaldehyde rate in the air exceeds safety limits. This has led us to the search of an easy and quick method to neutralize this vapour during the tissue sampling. We have pursued our aim using hydrogen peroxide which, in force of its oxidizing action, transforms formaldehyde into carbonic anhydride and water, which are two innocuous products.

[A case of diffuse hemangioma of the placenta]

The paper reports a case of diffuse placental hemangioma leading to intrauterine fetal death. Contrary to other cases reported in the literature, polyhydramnios, oligohydramnios and fetal malformations were not observed. The sole finding was a dilatation of the cardiac auricle, in particular on the right-hand side. It is hypothesised that fetal death was due to two concomitant factors: the severe hypoxemic state and the difficulty of venous drainage from the fetus to the mother owing to increased materno-fetal placental shunts.

[Anastomotic recurrence of colo-rectal cancer. Anatomo-surgical study]

A study was made of 20 patients operated for colorectal cancer with the aid of the University of Chieti Department of Pathological Anatomy. The histological preparations were carefully assessed for intramural diffusion of the tumour, and for the presence of hyperplastic and dysplastic processes in apparently healthy mucosa. The results were in full agreement with those reported in the literature.

[Neurinosarcoma of Vater's papilla. Apropos of a case]

Neurinosarcoma of Vater's ampulla is rarely observed. A case is presented in which the tumour did not occlude the ampulla and was thus detected intraoperatively. The head of the duodenum and the pancreas were ablated. Histological examination showed a fasciculated neoformation, in which the individual fasciculi ran parallel to or crossed each other. The nuclei displayed distinct atypical pictures. The little cytoplasm there was could only be clearly made out in areas involved in oedematous dissociation.

Heart rate response to held lung volume

It has been shown that respiratory sinus arrhythmia correlates fundamentally with lung volume changes. The correlation with thoracic circumference changes is incidental and quantitatively unreliable. Extensive measurements on one subject and limited measurements on four other subjects demonstrate the existence of a systematic relationship between heart rate and lung volume under reasonably static conditions, a high heart rate corresponding to the expiratory position and a low heart rate to the inspiratory position. This relation has been described successfully with an exponential equation.

heart rate and lung volume: exponential relation; heart rate: lung volume dependence; lung volume and thoracic circumference: calibration; respiration and heart rate: static lung volume effect; respiratory sinus arrhythmia: held lung volume and heart rate; sinus arrhythmia: static lung volume dependence; thoracic circumference and lung volume: calibration

Submitted on July 22, 1964