A small proton charge radius from an electron-proton scattering experiment.

Elastic electron-proton scattering (e-p) and the spectroscopy of hydrogen atoms are the two methods traditionally used to determine the proton charge radius, rp. In 2010, a new method using muonic hydrogen atoms1 found a substantial discrepancy compared with previous results2, which became known as the 'proton radius puzzle'. Despite experimental and theoretical efforts, the puzzle remains unresolved. In fact, there is a discrepancy between the two most recent spectroscopic measurements conducted on ordinary hydrogen3,4. Here we report on the proton charge radius experiment at Jefferson Laboratory (PRad), a high-precision e-p experiment that was established after the discrepancy was identified. We used a magnetic-spectrometer-free method along with a windowless hydrogen gas target, which overcame several limitations of previous e-p experiments and enabled measurements at very small forward-scattering angles. Our result, rp = 0.831 ± 0.007stat ± 0.012syst femtometres, is smaller than the most recent high-precision e-p measurement5 and 2.7 standard deviations smaller than the average of all e-p experimental results6. The smaller rp we have now measured supports the value found by two previous muonic hydrogen experiments1,7. In addition, our finding agrees with the revised value (announced in 2019) for the Rydberg constant8-one of the most accurately evaluated fundamental constants in physics.

[Evaluation of revascularization efficiency using near-infrared oximetry in patients with diabetic foot syndrome]. / Otsenka effektivnosti revaskulyarizatsii u patsientov s sindromom diabeticheskoi stopy metodom parainfrakrasnoi oksimetrii.

OBJECTIVE: To evaluate prognostic significance of tissue oximetry in healing of trophic defects in patients with diabetic foot syndrome (DFS) after endovascular revascularization. MATERIAL AND METHODS: In 42 patients with DFS, tissue oximetry was performed in angiosome projection with the FORE-SIGHT MC-2000 (CASMED) device before and the next day after revascularization of lower limb arteries. The 1st group included 30 patients with wound healing throughout 3 months, the 2nd group included 12 patients with amputation or no healing of trophic defects. RESULTS: Direct revascularization was more common in the 1st group (p=0.001). On the day after intervention, oxygen saturation (StO2) increased in all angiosomes in both groups (p<0.05). StO2 increment differed significantly between groups in all angiosomes except for point I (p<0.05). According to ROC analysis, StO2 increment by 4.5% in absolute values and 7.9% in percentage leads to trophic defect healing within 3 months (sensitivity and specificity were 76.7% and 66.7% for absolute values, 80% and 58.3% for percentage, respectively). CONCLUSION: Evaluation of StO2 in target angiosome may be valuable to predict trophic defect healing after endovascular surgery.

Surgical treatment in symptomatic stenosis of the carotid artery and persistent primitive hypoglossal artery. / Khirurgicheskoe lechenie pri simptomnom stenoze sonnoi arterii i persistiruiushchei émbrional'noi pod''iazychnoi arterii.

Persistent primitive hypoglossal artery is a rare variant of intrauterine anastomosis between the carotid and basilar arteries, which may remain in adults. The presence of this artery in carotid artery atherosclerosis increases the risks for stroke in the carotid and basilar basins. Our clinical case illustrates successful carotid endarterectomy in the presence of an ipsilateral persistent primitive hypoglossal artery under cerebral oximetry control.

[Mönkeberg's sclerosis: role of calcification in arterial lesions in patients with diabetes mellitus]. / Skleroz Menkeberga: rol' kal'tsinoza v porazhenii arterii u bol'nykh sakharnym diabetom.

The number of patients with diabetes mellitus has steadily been increasing. This disease is associated with the risk for the development of micro- and macroangiopathies. One of the variants of macroangiopathy is Mönkeberg's sclerosis characterized by the presence of calcification of the media of the arterial wall. This article is a literature review reflecting the role of calcification in arterial lesions in patients with diabetes mellitus, also covering the historical aspect of studying Mönkeberg's sclerosis. Special attention is paid to its morphological forms, aetiopathogenetic mechanisms of development, taking into account contemporary studies, demonstrating mechanisms of the effect of medial arterial calcification on haemodynamics and the risk for the development of cardiovascular complications. Also presented herein are the main non-invasive and invasive methods of its diagnosis.

[Role of cerebral oximetry in prediction of hyperperfusion syndrome after carotid endarterectomy]. / Rol' tserebral'noi oksimetrii v prognozirovanii sindroma giperperfuzii posle karotidnoi éndarteréktomii.

OBJECTIVE: The purpose of the study was to carry out a retrospective analysis of alterations in regional oxygenation (rSO2) of the brain at all stages of carotid endarterectomy (CEA) in order to detect predictors of ischaemia and hyperperfusion of the brain. PATIENTS AND METHODS: In a total of 169 patients during CEA under general anaesthesia we registered rSO2 after induction of narcosis, prior to carotid artery cross-clamping, at 2 minutes and each 10 minutes after cross-clamping, before re-establishing blood flow, at 2 and 5 minutes thereafter, and finally at the end of the operation. We evaluated the baseline parameters and intraoperative alterations in regional oxygenation depending on clinical and instrumental data. We also carried out a multivariate regression analysis in order to reveal significant risk factors for ischaemia and hyperperfusion. We analysed the ROC curves in order to determine the threshold value of a decrease and increase of rSO2 in ischaemia and hyperperfusion of the brain. RESULTS: After the multivariate analysis, an independent predictor turned out to be grade III arterial hypertension (OR 9.5, 95% CI: 1.1-82.7). It was revealed that the most significant predictor of the development of hyperperfusion syndrome was the absolute increase in rSO2 after re-establishing blood flow by more than 11.3. Sensitivity, specificity, positive and negative prognostic value of the parameter revealed amounted to 87.4, 83, 35 and 98.4%, respectively. CONCLUSIONS: The multivariate analysis performed demonstrated that only long-standing grade III arterial hypertension was a significant risk factor for the development of hyperperfusion syndrome after CEA. In our study, the most accurate parameter for the Fore-Sight oximeter was the maximum increase of the absolute value of rSO2 after re-establishing blood flow above 11.3 Cerebral oximetry is a non-invasive, simple to use and interpreter method making it possible to evaluate not only ischaemia but hyperperfusion of the brain during CEA and in the early postoperative period.

[Transradial approach in carotid stenting]. / Transradial'nyi dostup pri karotidnom stentirovanii.

A femoral approach is the main access in stenting of carotid arteries, mainly due to rapid training in how to perform the procedure and a possibility of using large-diameter catheters. However, this approach is not always feasible in atherosclerosis, tortuosity of lower-limb arteries and in certain anatomical peculiarities of the aortic arch. Using a transradial approach is based on the desire to diminish the incidence rate of haemorrhagic complications in the zone of the puncture and to avoid the necessity of a long-term bed rest. The findings obtained in numerous studies of coronary stenting and in a series of works on stenting of carotid arteries have demonstrated that the transradial approach reduces the risk of haemorrhage and local vascular complications. Our study was aimed at comparative analysis of the transradial versus transfemoral approache used in carotid stenting. We retrospectively analysed the results of transradial and transfemoral stenting of carotid arteries in a total of 168 patients. The operations had been performed in two centres over the period from 2012 to 2017. We evaluated the clinical and angiographic data, technical aspects of the operations, as well as the outcomes and complications. In particular, we compared such complications as stroke, transitory ischaemic attack, myocardial infarction and local complications of the approach. We carried out a univariate analysis of the risk for the development of complications depending on the method of the approach. Stenting of carotid arteries had been performed in 75 patients through the radial approach and in 93 patients via the femoral one. Comparing the two groups, the main clinical and angiographic data appeared to have no statistically significant differences. Various techniques of catheterization had been used depending upon anatomical peculiarities. The success of the procedure was achieved in 100% of cases, with the frequency of conversion amounting to 4% for the radial approach and to 1% for the femoral one (p=0.087). Amongst complications encountered, disabling stroke was revealed in two (1.2%) patients and minor stroke in four (2.4%). The groups did not differ by the incidence of neurological complications. Within 30 postoperative days neither lethal outcomes nor myocardial infarction were registered. Neither were there haemorrhagic events or other approach-related complications, however in the transradial-approach group, seven (9.3%) patients were found to have developed asymptomatic occlusions of the radial artery. The duration of the operation, the radiation load, and the length of hospital stay had no statistically significant differences depending on the approach used. Hence, the transradial approach is an effective and safe method in stenting of carotid arteries. In patients with high risk of haemorrhagic complications from the side of the vascular approach and with difficult anatomy of the aortic arch and its branches, hampering catheterization of the carotid artery via the femoral approach, the radial artery may be considered as an advantageous site of access.

[POSSIBILITIES FOR THE SURGICAL TREATMENT OF PATIENTS WITH EXTENSIVE MALIGNANT CHEST WALL NEOPLASMS].

The authors consider possibilities for the surgical treatment of patients with extensive malignant chest wall neoplasms. It is argued that combinedsugical interventions and resection of the affected parts of the chest wall together with the tumour and the use of plastic procedures allow to arrest further development of severe complications in the majority of patients and create conditions for the continuation of the anti-tumour treatment. Plastic and reconstructive surgery permits to extend operability limits and thereby improve the quality of the treatment and increase life expectancy of the patients with extensive tumorigenic process.

[REMOVAL OF FLOATING THROMBUS FROM INFERIOR VENA CAVA IN A PATIENT WITH GIANT RECURRENT UTERINE LEIOMYOSARCOMA].

This paper reports successful combined cytoreductive surgical intervention on a patient with giant recurrent uterine leiomyosarcoma complicated by tumour thrombosis of left ovarian and left renal veins and inferior vena cava. After the comprehensive examination confirmed good prospects for conservative therapy, surgery was performed on 07.02.12 including laparotomic resection of the giant tumour from the abdominal cavity and small pelvis, sigmoid and rectal resection, formation of end-to-end descendorecto-anastomosis, left-hand nephrectomy, removal of tumour thrombus from the suprarenal part of inferior vena cava. The postoperative period was uneventful. No signs of pulmonary thromboembolism were recorded intra- and postoperatively. Wound healing occurred by primary intention, the sutures were removed on day 12 after surgery. The patient was discharged to be further treated on an outpatient basis. Pathological changes in the lower limbs were absent. The patient recovered and leads an active lifestyle. The follow-up examination (July 2012, March 2014) confirmed her healthy status and the absence of signs suggesting the risk of relapse and progress of the neoplastic process.

[Results of surgical treatment of patients with solid malignant chest tumours and superior vena cava syndrome].

Superior vena cava syndrome results from blood flow disturbances caused by compression or tumour invasion of the superior vena cava and its tributaries. In most cases, malignant lung tumours are responsible for its development. In 1995-2010, we performed surgical treatment of 55 patients with malignant chest neoplasms and superior vena cave syndrome. Vertical sternotomy was employed most frequently. Some patients additionally underwent antero-lateral thoracotomy to facilitate the surgical approach. Polytetrafluoroethylene prostheses 18-20 mm in diameter (Russia) were used to superior vena cava. Radical and cytoreductive surgery was the method of choice in 60 and 40% of the patients respectively. The signs of obstruction disappeared in all patients immediately after surgery. 21.8% of the patients died during the early postoperative period, 5 ones survived without signs of relapses. Median survival was 21 months.

New Measurement of the π0 radiative decay width.

High precision measurements of the differential cross sections for π0 photoproduction at forward angles for two nuclei, 12C and 208Pb, have been performed for incident photon energies of 4.9-5.5 GeV to extract the π0→γγ decay width. The experiment was done at Jefferson Lab using the Hall B photon tagger and a high-resolution multichannel calorimeter. The π0→γγ decay width was extracted by fitting the measured cross sections using recently updated theoretical models for the process. The resulting value for the decay width is Γ(π0→γγ)=7.82±0.14(stat)±0.17(syst) eV. With the 2.8% total uncertainty, this result is a factor of 2.5 more precise than the current Particle Data Group average of this fundamental quantity, and it is consistent with current theoretical predictions.

[Use of high-energy intraluminal brachytherapy in radio- and radiochemotherapy for anal cancer].

Complete local response to radio- and chemoradiation for anal cancer was improved due to use of high-energy dosage of intraluminal brachytherapy (complete clinical regression (chemoradiation)--85.7%; combined irradiaton--75%). No signs of tumor progression have been reported in 20 survivors (median duration--21.6 months) (mean recurrence-free survival--12.5 months). Loco-regional relapse was in 4, local--2 patients. Intrapelvic lymph nodes were involved in 2 cases of previously morphologically confirmed regression of primary tumor. 18-month-long recurrence-free survival was in 86.3%, colostomy-free--91.6%. When combined with distant irradiation (+/-chemotherapy), brachytherapy is a relatively effective, safe and well tolerated procedure.

[Operative isolated chemohyperthermal perfusion of the lung with ablation of pulmonary metastases].

The authors have got their first experience with chemohyperthermal perfusion of the lung in 4 patients. The method and technique of the operation of ablation of metastases in the lungs with preliminary chemohyperthermal perfusion are described. All the patients survived the operative interventions.

Precision measurement of the neutral pion lifetime.

The explicit breaking of the axial symmetry by quantum fluctuations gives rise to the so-called axial anomaly. This phenomenon is solely responsible for the decay of the neutral pion π0 into two photons (γγ), leading to its unusually short lifetime. We precisely measured the decay width Γ of the [Formula: see text] process. The differential cross sections for π0 photoproduction at forward angles were measured on two targets, carbon-12 and silicon-28, yielding [Formula: see text], where stat. denotes the statistical uncertainty and syst. the systematic uncertainty. We combined the results of this and an earlier experiment to generate a weighted average of [Formula: see text] Our final result has a total uncertainty of 1.50% and confirms the prediction based on the chiral anomaly in quantum chromodynamics.

[Age-related features of cardiomyocyte ultrastructure of the effluent region of the right ventricle in patients with Fallot's tetralogy]. / Vozrastnye osobennosti ul'trastruktury kardiomiotsitov vyvodnogo otdela pravogo zheludochka bol'nykh tetradoi Fallo.

Ultrastructural signs of compensatory hypertrophy (channels of granular endoplasmatic reticulum well developed Golgi complex, dilatation of T-system channels, alterations of the myofibrillar structure, appearance of non-parallel myofibrills, groups of small mitochondria, numerous intercalated disci) were found in the cardiomyocytes of the right ventricle effluent region of the adult (18-40 years) and young (6-12 years) patients with tetralogy of Fallot. Some cells showed degenerative changes-a transition of the hypertrophic cells in the stage of decompensation.

Observation of a narrow charm-strange meson D(+)(sJ)(2632)-->D(+)(s)eta and D(0)K(+).

We report the first observation of a charm-strange meson D(+)(sJ)(2632) at a mass of 2632.5+/-1.7 MeV/c(2) in data from SELEX, the charm hadro-production experiment E781 at Fermilab. This state is seen in two decay modes, D(+)(s)eta and D0K+. In the D(+)(s)eta decay mode we observe a peak with 101 events over a combinatoric background of 54.9 events at a mass of 2635.4+/-3.3 MeV/c(2). There is a corresponding peak of 21 events over a background of 6.9 at 2631.5+/-2.0 MeV/c(2) in the decay mode D0K+. The decay width of this state is <17 MeV/c(2) at 90% confidence level. The relative branching ratio Gamma(D0K+)/Gamma(D(+)(s)eta) is 0.14+/-0.06. The mechanism that keeps this state narrow is unclear. Its decay pattern is also unusual, being dominated by the D(+)(s)eta decay mode.

First observation of the doubly charmed baryon Xi(+)(cc).

We observe a signal for the doubly charmed baryon Xi(+)(cc) in the charged decay mode Xi(+)(cc)-->Lambda(+)(c)K-pi(+) in data from SELEX, the charm hadroproduction experiment at Fermilab. We observe an excess of 15.9 events over an expected background of 6.1+/-0.5 events, a statistical significance of 6.3sigma. The observed mass of this state is 3519+/-1 MeV/c(2). The Gaussian mass width of this state is 3 MeV/c(2), consistent with resolution; its lifetime is less than 33 fs at 90% confidence.