A comprehensive study to reveal the potential of a more sustainable ultra-high performance enantioselective reversed-phase chromatography on Pirkle-type stationary phase, with Whelk-O1 as a case study.

In this study, we aimed to make enantioselective chromatography more sustainable, more sensitive, and compatible with aqueous formulations analysis and ESI-MS. To achieve this, we examined the effects of transitioning from normal-phase chromatography (which uses hydrocarbon-based solvents) to reversed-phase chromatography (using mobile phases based on water) using broad-spectrum Whelk-O1 columns as a critical study. For the first time, we holistically compared the thermodynamics and kinetics of the two elution modes in order to answer the question of whether same-column chemistry can effectively separate the compounds even in reversed-phase mode and found, unexpectedly, that reversed-phase chromatography using acetonitrile as the organic modifier was competitive from a kinetic standpoint. We also evaluated the effectiveness of three organic modifiers simultaneously on a sample of 11 molecules already resolved in NP conditions with different resolutions and achieved a resolution value of 1.5 for 91% and a resolution value of 2 for 82% of cases. Finally, we separated three racemates (within a k factor of 9) using only 480 µL of solvent per chromatographic run on a millibore column of 1 mm I.D., demonstrating that our approach allows for greener chromatographic separations.

GRP78 promotes the osteogenic and angiogenic response in periodontal ligament stem cells.

Periodontitis is a progressive disease that ultimately leads to bone and tooth loss. A major consequence of periodontal disease is the inability to regain lost bone in the periodontium. The importance was demonstrated of glucose-regulated protein-78 (GRP78) in the osteogenic differentiation of periodontal ligament stem cells and their potential use for regeneration of the periodontium. Previous studies have shown the relationship between GRP78 and dentine matrix protein-1 (DMP1). The importance of this receptor-ligand complex in supporting the process of osteogenesis and angiogenesis was confirmed in this study. To show the function of GRP78 in mineralised tissues, transgenic periodontal ligament stem cells (PDLSCs) were generated in which GRP78 was either overexpressed or silenced. Gene expression analysis of the cells cultured under osteogenic conditions showed an increase in key osteogenic genes with the overexpression of GRP78. RNA-Seq analysis was also performed to understand the transcriptome profile associated with genotype changes. Using the database for annotation, visualisation, and integration discovery (DAVID) for the functional enrichment analysis of differentially expressed genes, the upregulation of genes promoting osteogenesis and angiogenesis with GRP78 overexpression was demonstrated. Alizarin red staining and scanning electron microscopy analysis revealed matrix mineralisation with increased calcium deposition in GRP78 overexpressing cells. The in vivo osteogenic and angiogenic function of GRP78 was shown using a subcutaneous implantation rodent model. The results suggested that GRP78 in PDLSCs can regulate the expression of both osteogenesis and angiogenesis. Therefore, GRP78 could be considered as a therapeutic target for repair of diseased periodontium.

Epidemiology of distal radius fractures: a detailed survey on a large sample of patients in a suburban area.

BACKGROUND: Literature lacks data on correlations between epidemiology and clinical data of patients with distal radius fractures (DRFs). AIM: The aim of this study was to present a detailed epidemiologic survey of a large consecutive series of patient with DRFs. MATERIALS AND METHODS: This retrospective study included 827 consecutive patients (579 females, 248 men) who sustained a DRFs in the last 5 years. All fractures were radiographically evaluated. DRFs were classified according to Association of Osteosynthesis classification. Data on age, gender, side, period in which fracture occurred, and fracture mechanism were collected. Statistical analysis was performed. RESULTS: The patients' mean age was 60.23 [standard deviation (SD) 16.65] years, with the left side being most frequently involved (56.1%). The mean age of females at the time of fracture was significantly higher than that of males. The most frequent pattern of fracture was the complete articular fracture (64.3%), while the most represented fracture type was 2R3A2.2 (21.5%). Regarding the period in which the fracture occurred, 305 DRFs (37.5%) were observed in the warmer months and 272 (33.4%) in the colder months. Low-energy trauma occurring outside home was found to be the major cause of DRF throughout the year. In both genders, trauma mechanism 2 was more frequent (59.4% F; 31.9% M; p < 0.01). A bimodal distribution of fracture mechanisms was found in males when considering the patient's age with a high-energy mechanism of fracture (3 and 4), identified in 21% (n = 52) of males aged 18-45 years, and a low-energy mechanism (1 and 2) was observed in 39.9% (n = 99) of males aged > 45 years. A significant correlation between all trauma mechanisms (from 1 to 6) and different fracture patterns (complete, partial, and extraarticular) was found (p value < 0.001). The mean age of patients with extraarticular fractures (mean age 61.75 years; SD 18.18 years) was higher than that of those with complete (mean age 59.84 years; SD 15.67 years) and partial fractures (mean age 55.26 years; SD 18.31 years). Furthermore, considering different fracture patterns and patient age groups, a statistically significant difference was found (p < 0.001). CONCLUSIONS: DRFs have a higher prevalence in females, an increase in incidence with older age, and no seasonal predisposition. Low-energy trauma occurring at home is the main cause of fracture among younger males sustaining fractures after sports trauma; Complete articular is the most frequent fracture pattern, while 2R3A2.2 is most frequent fracture type. LEVEL OF EVIDENCE: Level IV; case series; descriptive epidemiology study.

Wide resection for giant-cell tumor of the distal radius: which reconstruction? A systematic review of the literature and pooled analysis of 176 cases.

Giant-cell tumor (GCT) is often more aggressive when located in the distal radius, and wide resection is then the gold-standard. No single reconstruction protocol is recommended, and the technique depends upon the surgeon's preferences. The aim of the present review was to determine the recurrence rate of GTC of the distal radius after intralesional treatment, to assess the results, advantages and complications of the various surgical techniques, and to draw up a decision-tree for surgical indications. The review of literature was performed in the main healthcare databases, searching for studies that reported results of wide resection and reconstruction of distal radius GCT. Local recurrence rates, metastasis rates, reconstruction techniques and respective results and complications were evaluated and analyzed. Sixteen studies were selected, for a total population of 226 patients; 6.0% and 0.9% experienced local recurrence and lung metastasis, respectively. Arthroplasty with non-vascularized or vascularized ipsilateral fibula were the most common techniques and were associated with the highest satisfaction rates: 86.4% and 88.0%, respectively. Arthroplasty with allograft presented a MusculoSkeletal Tumor Society (MSTS) score of 79.2% and arthroplasty with custom-made prosthesis presented an MSTS score of 81.8%. Arthrodesis was performed in 46 cases, with an MSTS score of 82.7%. Arthroplasty techniques are the most common in literature; they are used in patients who wish to conserve joint motion. Reconstruction with non-vascularized fibula seems to provide the best results, with lower morbidity. Arthrodesis is usually reserved for heavy manual workers or in case of arthroplasty failure.

Glenoid version: the role of genetic and environmental factors on its variability. An MRI study on asymptomatic elderly twins.

BACKGROUND: Glenoid version is the most variable parameter of the shoulder joint. No authors investigated if intrinsic genetic factors or influences from extrinsic sources are responsible for its variability. AIM: We compared glenoid version between elderly monozygotic and dizygotic twins intending to separate the contributions of genetics from shared and unique environments. METHODS: Glenoid version of the dominant shoulder was assessed by MRI using Friedman's method in 30 pairs of elderly twins (16 monozygotic-14 dizygotic; mean age ± SD: 63.72 ± 3.37, 53-72). Heritability was estimated as twice the difference between the intraclass correlation coefficients for monozygotic and dizygotic pairs. The influence of shared environment was calculated as the difference between monozygotic correlation coefficient and the heritability index. According to job category, one way analysis of variance was used to estimate the differences between groups in the total sample and within zygosity groups. RESULTS: Glenoid version angle in monozygotic and dizygotic twins was -2° (SD: 2°) and -3° (SD: 3°), respectively (p = 0.334). Heritability index was 0.98, while the contributions of shared and unique environment were 0 and 0.02, respectively. According to working classes, no significant differences were found between the groups (p = 0.732, F = 0.31). CONCLUSIONS: Glenoid version is mainly genetically determined and only marginally influenced by environments.Level of evidence: III.

The neutrophil/lymphocyte ratio as a prognostic factor in COVID-19 patients: a case-control study.

OBJECTIVE: SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) has been identified in China as responsible for viral pneumonia, now called COVID-19 (Coronavirus Disease 2019). Patients infected can develop common symptoms like cough and sore throat, and, in severe cases, acute respiratory syndrome and even death. To optimize the available resources, it is necessary to identify in advance the subjects that will develop a more serious illness, therefore requiring intensive care.The neutrophil / lymphocyte ratio (NLR) parameter, resulting from the blood count, could be a significant marker for the diagnosis and management of risk stratification. PATIENTS AND METHODS: A retrospective, single-center case-control observational study was conducted. The differential cell count of leukocytes, the NLR and the clinical course of patients hospitalized in intensive care with COVID-19 were analyzed, comparing them with other patients (COVID-19 and non-COVID-19) and healthy individuals selected among workers of the Teaching Hospital Policlinico Umberto I in Rome. RESULTS: 370 patients (145 cases and 225 controls) were included in the case-control study, 211 males (57%) and 159 females (43%). The average age of the population was 63 years (SD 16.35). In the group of cases, out of 145 patients, 57 deaths and 88 survivors were recorded, with a lethality rate of 39.3%. The group of cases has an NLR of 7.83 (SD = 8.07), a much higher value than the control group where an NLR of 2.58 was recorded (SD = 1.93) (p <0.001). The Neutrophils / Lymphocytes ratio may prove to be a diagnostic factor for COVID-19, an NLR> 3.68 revealed an OR 10.84 (95% CI = 6.47 - 18.13) (p <0.005). CONCLUSIONS: The value of NLR considered together with the age variable allows a risk stratification and allows the development of diagnostic and treatment protocols for patients affected by COVID-19. A high neutrophil to lymphocyte ratio suggests worse survival. Risk stratification and management help alleviate the shortage of medical resources and reduce the mortality of critically ill patients.

Analysis of the risk of a secondary displacement in conservati- vely treated paediatric distal radius metaphyseal fractures. A multicentric study.

OBJECTIVES: Distal radius fractures represent one of the most fre-quent injuries in children. The treatment of choice is a closed reduction followed by immobilisation in plaster cast; the immediate recourse to osteosynthesis with Kirschner wires is only reserved for certain cases. The displacement rate reported in the literature is 21-39%. The aim of this study is to retrospectively evaluate the risk factors for a secondary displacement of metaphyseal radius fractures in a paediatric population treated in three different centres. MATERIALS AND METHODS: The initial treatment for all 360 patients examined was a closed reduction under general anaesthesia and im-mobilisation in an above elbow cast for 4 weeks. The pre-operative displacement, residual post-reduction displacement and possible di-splacement at 7 and 14 days of follow-up were all assessed clinically and radiographically. RESULTS: A loss of reduction was reported in 102 cases; 51 under-went an additional reduction procedure - some followed by osteo-synthesis - while in the remaining 51 cases, the loss of reduction was acceptable in relation to the expectation of remodelling. The most statistically significant variable for the occurrence of a secondary displacement is a severe primary displacement. The association with the ulna fracture is not significantly correlated. The quality of the plaster cast is important for maintaining the reduction. There are a few things to consider as indicators for a second procedure: age, time elapsed from moment of fracture, fracture site and the absence of an acceptable reduction. CONCLUSIONS: In our experience, a reduction followed by osteo-synthesis with Kirschner wires should be considered the treatment of choice in fractures with a high risk of secondary displacement, namely those with severe initial displacement or unsatisfactory reduction.

Outcome and technical consideration of conversion total hip arthroplasty after failed fixation of intracapsular and extracapsular hip fractures: Are they really that different?

INTRODUCTION: Conversion Total Hip Arthroplasty (cTHA) is a rescue strategy for proximal femur osteosynthesis failures. However, it is unclear whether cTHAs performed for extra-capsular fracture fixation failures (ECF) or for intra-capsular fracture fixation failures (ICF) share the same complexity and efficacy. The purpose of our study was to compare cTHAs performed on pre-existing ICFs and pre-existing ECFs, focusing on surgical complications and functional outcomes in both groups. METHODS: An observational retrospective study was conducted on cTHA patients, treated between 2014 and 2018, divided into 2 groups: ICF-group and ECF-group. The main outcomes were: type of implant used, duration of surgery, need for transfusions, incidence of complications, functional outcomes. RESULTS: 28 patients were included (15 in the ECF group and 13 in the ICF group); the average follow-up was of 31 ± 17.3 months. No significant differences were identified in terms of the type of implant used and duration of surgery. The number of transfused patients was 4 in the ICF group and 12 in the ECF group (p = 0.02); the average transfused units were 0.4 ± 0.7 in the ICF group and 1.3 ± 0.9 in the ECF group (p = 0.01). The incidence of complications - an infection and a dislocation, both of which occurred in the ICF group - and functional outcomes did not present significant differences. CONCLUSION: The conversion surgery on ECFs patients is technically more difficult for the surgeon and prone to greater blood loss. The outcomes are satisfactory and overlap between the two groups.

RADIAL head arthroplasty: does ligaments repair influence outcomes? A minimum two years follow-up radiographic multi-center study.

PURPOSE: The current indication for comminuted radial head fractures is radial head arthroplasty (RHA). The main purpose of this study was to investigate any statistical differences in terms of prosthesis revision or removal and radiographic degenerative changes by comparing patients who underwent RHA and ligaments repair to those who underwent only RHA implant at minimum two years follow-up. The secondary aim was to delineate a trend profile of RHA implants. METHODS: All patients who underwent RHA surgery for traumatic pathology between January 2012 and December 2017 were eligible. Two researchers independently and retrospectively reviewed the patients' charts and collected the following data: type of prosthesis, associated surgical procedures and revision surgery. They also looked for any radiographic sign of prosthesis loosening, overstuffing, capitellar osteopenia, heterotopic ossification and degenerative changes. No clinical evaluation was performed. RESULTS: In 6 years, 124 RHA were implanted (74 female, 50 male, mean age 56). The main diagnoses were: terrible triad, trans-olecranon fracture and isolated radial head fracture. It was found no significant statistical difference between the 2 groups; nevertheless, the cohort of patients that underwent ligaments repair had a lower revision rate in comparison with the other. Suture of the annular ligament seems to be critical. The overall revision rate was 10.5%. CONCLUSION: This multi-center study found no evidence that ligaments repair, as an associated surgical procedure, improves RHA longevity, except for annular ligament. Nevertheless, it seems to prevent degenerative changes at midterm follow-up.

Consensus paper on postural dysfunction: recommendations for prevention, diagnosis and therapy.

Good fundamentals of posture and balance are essential for the efficient performance of both simple daily tasks and more complex movement patterns. In particular, postural balance is the ability to keep the body in equilibrium and to regain balance after the shift of body segments: postural control mechanisms of integration of the visual, vestibular and foot afferential channels contribute to this. This document provides recommendations based on scientific evidence, clinical practice, and consensus between experts concerning the prevention, diagnosis, and treatment of postural dysfunction at the three stages of life as the developmental age, adult age, and old age > 65 years and follows the "National Guidelines on Classification and Measuring of Posture and its Dysfunctions" per the Italian Ministry of Health (December 2017). The paper answers four main questions: i) "Which measures can be adopted to prevent postural dysfunctions?" ii) "What can we do in order to make a correct diagnosis of postural dysfunction?" iii) "What are the correct treatment programs for postural dysfunctions?" iv) Which professional competencies and experiences are useful for preventing, diagnosing and treating postural dysfunctions? By the Consensus of the Experts and the scientific evidence, emerge that the approach to postural dysfunctions requires a multidisciplinary and interdisciplinary team. Furthermore, rehabilitation treatment interventions must be specific to the age groups that have been indicated, to consider the integration of the main systems and subsystems of postural control that change with age.

A proposal of rehabilitative approach in the rare disease "De Barsy Syndrome": case report.

De Barsy syndrome is an autosomal recessive condition characterized by an progeroid appearance with distinctive facial features and cutis laxa. Ophthalmological, orthopedic, and neurological anomalies are generally also present. This syndrome is rare and the complex therapeutic management, from a surgical but also rehabilitative point of view, has not been recognized. The aim of this paper is to describe a possible rehabilitative protocol, after an orthopedic surgical treatment, in a child with De Barsy Syndrome. A 6-year-old boy was born with a congenital bilateral hip dysplasia associated with bilateral congenital foot deformity (vertical talus). Moreover, he showed stereotypic dyskinetic movements and psychomotor delay with cognitive impairment and absent language; the sitting position was maintained with orthoses to support the trunk control and the standing position was not acquired. He was treated with pinstripe knee-highs for the foot and double nappy for the hips. At 19 months old, he underwent a two stage surgical approach for a bilateral pronated valgus foot with severe talonavicular subluxation. Satisfactory hip range of motion was achieved by conservative treatment alone. Afterwards, for the foot laxity and the flat-pronated foot corrective shoes were prescribed. The main rehabilitative goals were: attention improvement, visual exploration for foot-eye and hand-eye coordination, encourage the essential prerequisites of language, controlling the upright position using support, improving hip-knee-foot relationship, improving load transfer between the right and left sides of the body, and bimanual coordination. The rehabilitation process lasted six months, three times a week, for a time from 30 minutes to 60 minutes per session. The results were encouraging and the patient acquired the possibility of sitting with the indicated postural system, the possibility of assuming an upright position and taking a few steps with the aid of rollator with a postural stabilization system for the pelvis.

A novel neurocognitive rehabilitation tool in the recovery of hemiplegic hand grip after stroke: a case report.

Stroke has significant physical, psychological and social consequences. Recent rehabilitation approaches suggest that cognitive exercises with dual-task (sensory-motor) exercises positively influence the recovery and function of the hemiplegic hand grip. The purpose of this study was to describe a rehabilitation protocol involving the use of a new neurocognitive tool called "UOVO" for hand grip recovery after stroke. A 58-year-old right-handed male patient in the chronic stage of stroke, presenting with left-sided hemiparesis and marked motor deficits at the level of the left hand and forearm, was treated with the UOVO, a new rehabilitation instrument based on the neurocognitive rehabilitation theory of Perfetti. The patient was evaluated at T0 (before treatment), T1 (after treatment) and T2 (2 months of follow-up). At T2, the patient showed improvements of motor functions, shoulder, elbow and wrist spasticity, motility and performance. This case report explores the possibility of improving traditional rehabilitation through a neurocognitive approach with a dual-task paradigm (including motor and somato-sensory stimulation), specifically one involving the use of an original rehabilitation aid named UOVO, which lends itself very well to exercises proposed through the use of motor imagery. The results were encouraging and showed improvements in hemiplegic hand grip function and recovery. However, further studies, in the form of randomized controlled trials, will be needed to further explore and confirm our results.

Shoulder adhesive capsulitis and hypercholesterolemia: role of APO A1 lipoprotein polymorphism on etiology and severity.

PURPOSE: Relationship between shoulder adhesive capsulitis (AC) and hypercholesterolemia is known. The connecting link might be represented by the correlation between HDL and transforming growth factor beta (TGF-ß): normally, HDLs stimulate TGF-ß expression; the latter is employed in the development of fibrous tissue. We assess whether the presence of the Apo-A1-G75A-polymorphism, which is correlated to an enhanced HDL function, could be a risk factor for the genesis and severity of AC. METHODS: Peripheral blood samples of 27 patients [7M; 20F, mean age 54.81 (41-65)] with AC and hypercholesterolemia were submitted to polymerase chain reaction in order to evaluate the Apo-A1-G75A-polymorphism. Genome database was used as control. Two categories were obtained according to AC severity: type I (active forward flexion ≥ 100°) and type II (< 100°). Data were submitted to statistics. RESULTS: The prevalence of Apo-A1-G75A-polymorphism in the studied group and in the control group was 22.2% (10AG; 1AA; 16GG) and 19% (OR 1.22, IC 0.59-2.53, p > 0.05), respectively. Patients with type I and II capsulitis were 11 [flexion 148.0° (range 100°-165°)] and 16 [flexion 82.5° (range 50°-95°)], respectively. The prevalence of Apo-A1-G75A in type I was 18.1% (2AG; 9GG) and in type II was 56.3% (8GA; 1AA; 7GG), respectively (RR 1.87, IC 1.005-3.482, p < 0.05). CONCLUSIONS: Apo-A1-G75A-polymorphism is not necessary for the genesis, but it is a risk factor for severity of AC. LEVEL OF EVIDENCE: III.

The treatment of femoral fractures in children with cerebral palsy.

OBJECTIVE: The purpose of this study is to retrospectively evaluate a group of children affected by cerebral palsy with a recent femoral fracture, and to analyse the results and complications in relation to the treatment used. MATERIALS AND METHODS: The analysis was performed on 36 children (21 M, 15 F, 8-14 years old) with cerebral palsy (7 diplegia, 28 tetraparesis, 1 hemiplegia) with a metaphyseal or a diaphyseal femoral fracture. The patients were subdivided into two groups according to their Gross Motor Function Classification System (GMFCS) level: level 2-3 (9 patients) and level 4-5 (27 patients), evaluating the presence of complications and malunions for each group at the end of each follow up. RESULTS: The fractures were displaced in 24 patients and nondisplaced in 12 patients. In 26 cases the treatment involved a closed reduction and immobilisation in a long leg hip spica cast for 7 weeks, while in 10 cases the treatment involved an open reduction-internal fixation (ORIF) followed by a 3-week period in a plaster coated fracture bandage. CONCLUSIONS: Taking into consideration the maximum possible recovery of function, an ORIF is preferable to prevent malunion, particularly in distal metaphysis and distal shaft fractures. In the GMFCS level 2-3 patients, surgery has allowed to recover, or at least maintain, the pre-fracture functional level, while in patients with GMFCS level 4-5, it has allowed to reduce the immobilisation times and prevent the development of decubitus lesions.

Cannabis through the looking glass: chemo- and enantio-selective separation of phytocannabinoids by enantioselective ultra high performance supercritical fluid chromatography.

By using the Inverted Chirality Columns Approach (ICCA) we have developed an enantioselective UHPSFC method to determine the enantiomeric excess (ee) of (-)-Δ9-THC in medicinal marijuana (Bedrocan®). The ee was high (99.73%), but the concentration of the (+)-enantiomer (0.135%) was not negligible, and it is worth a systematic evaluation of bioactivity.

Assessment and therapeutic choice in septic arthritis of the hip in an intravenous drug abuser: case report at 14 years follow-up and review of literature.

INTRODUCTION: Osteoarticular infections are found frequently in drug addicted individuals, representing one of the main reasons for their hospitalization. Through inoculation, the pathogenic agents can enter the individual's system directly through the skin or parenterally, transmitted, that is, through syringes and other objects used during such practice. In these particular conditions, or when the medical history is vague, a warranted suspicion and the execution of targeted research can help in the diagnosis of high-risk patients such as addicts. DISCUSSION: With this paper, the Authors are presenting a case of septic arthritis in the hip joint, in a drug addicted patient with the habit of injecting narcotics into the femoral vein, in correspondence of the anatomical region known as the triangle of Scarpa. Following an examination of the bacterial culture samples taken by arthrocentesis, the S. Aureus infection was identified and a targeted antibiotic therapy (coxacillin and aminoglycosides) was prescribed. After one year, with clinical examination and medical scans resulting negative for infection, there was a remaining deformity of the femoral head and, therefore, a total hip arthroplasty (THA) was performed. The 14 year post-operative clinical examination and medical scan check-up showed a complete articular functionality and recovery of normal daily and work related activities.

Fluoroscopic freehand and electromagnetic-guided targeting system for distal locking screws of humeral intramedullary nail.

PURPOSE: The current techniques used to lock distal screws for the nailing of long bone fractures expose the surgeons, radiologists and patients to a hearty dose of ionizing radiation. The Sureshot™ Distal Targeting System is a new technique that, with the same results, allows for shorter surgery times and, consequently, less exposure to radiation. MATERIALS AND METHODS: The study was performed on 59 patients (34 males and 25 females) with a simple humerus fracture diagnosis, type 1.2.A according to the AO classification, who were divided into two groups. Group 1 was treated with ante-grade intramedullary nailing with distal locking screws inserted with a freehand technique. Group 2 was treated with the intramedullary nail using the Sureshot™ Distal Targeting System. Two intra-operative time parameters were evaluated in both groups: the time needed for the positioning of the distal locking screws and the time of exposure to ionizing radiations during this procedure. RESULTS: Group 2 showed a lower average distal locking time compared to group 1 (645.48″ vs. 1023.57″) and also a lower average time of exposure to ionizing radiation than in group 1 (4.35″ vs. 28.96″). CONCLUSION: The Sureshot™ Distal Targeting System has proven to be equally effective when compared to the traditional techniques, with the added benefits of a significant reduction in both surgical time and risk factors related to the exposure to ionizing radiation for all the operating room staff and the patient.

Atropisomerism in 3-arylthiazolidine-2-thiones. A combined dynamic NMR and dynamic HPLC study.

Sterically hindered 3-arylthiazolidine-2-thiones were prepared by a solvent-free reaction with arylisothiocyanates and 1,4-dithiane-2,5-diol. Atropisomerism was observed in two compounds (3 and 4, aryl = 1-naphthyl and 2-methylnaphth-1-yl), whose rotational energy barriers were measured using dynamic NMR and dynamic HPLC. The experimental analyses were supported by DFT calculations. Thermally stable atropisomers were obtained by dehydration of compounds 3 and 4 and the absolute configuration of the atropisomers of compound 6 was determined by theoretical simulation of the ECD and VCD spectra.