Third Ventricular Colloid Cyst, New Surgical Classification.

BACKGROUND: This research discusses colloid cyst surgical concerns, with an emphasis on the value of a novel surgical classification based on anatomical sites. In the study, 59 patients who underwent surgical intervention between 2009 and 2022 and were diagnosed with colloid cysts via computed tomography scan and magnetic resonance imaging participated. METHODS: There were more male cases than female ones (57.6%). The majority of patients presented with headache (79%), followed by abnormal gait (12%), visual blurring (5%), and seizures (4%). RESULTS: In this study, we present a new surgical classification based on anatomical locations, distinguishing 4 types: open Monro type (50.84%), closed Monro type (23.72%), retroforaminal type (13.55%), and interforniceal type (11.86%). CONCLUSIONS: In summary, the surgical classification that has been suggested provides significant insights into the varied anatomical sites where colloid cysts might be found. Microneurosurgeons significantly need to be oriented about the possible sites of colloid cysts through this classification to achieve complete and curative resection and reduce the likelihood of recurrence.

Optical impressions assessment for overlay restorations with rubber dam: A clinical trial.

OBJECTIVE: The possibility of making impressions of teeth prepared with a rubber dam in place has been proposed; however, this requires trimming and rescanning the mesh, which has been described as a cause of accuracy loss. This study aims to clinically determine whether overlay restorations obtained from a scan with a rubber dam in place have equivalent marginal fit, contact points, and occlusal fit to the same type of restorations obtained from a scan without a rubber dam. MATERIAL AND METHODS: Thirty patients who underwent overlay restoration of a molar with at least one neighbouring tooth were selected. After tooth preparation, two scans were performed: one without a rubber dam and the other with a rubber dam. Restorations were randomly created from one scan or another. The marginal fit, interproximal contact points, and occlusal fit were evaluated clinically. Two meshes, with and without rubber dams, were also compared. RESULTS: No significant differences were observed in the clinical evaluation of the overlays made of the two meshes. The trueness of the mesh from the impression made with a rubber dam with respect to the mesh without a rubber dam was about 40 µm in the critical areas of the preparation (margins, intaglio, and interproximal contact points). CONCLUSIONS: The results of this study show that under the conditions performed and with the equipment used, there are no significant clinical differences between overlay restorations made from a scan with a rubber dam and those made from a scan without a rubber dam. CLINICAL SIGNIFICANCE: Scanning with a rubber dam in place may be a valid option for certain types of restorations under certain clinical conditions.

Exploring quantum computational, molecular docking, and molecular dynamics simulation with MMGBSA studies of ethyl-2-amino-4-methyl thiophene-3-carboxylate.

2-aminothiophenes derivative, Ethyl-2-amino-4-methyl thiophene-3-carboxylate (EAMC) has been synthesized, characterized, and investigated quantum chemically. It was experimentally investigated by different spectroscopic methods like- NMR (1H-NMR and 13C-NMR), FT-IR, and UV-Visible. B3LYP method and 6-311++G(d,p) basis set were employed for optimization of molecular structure and calculation of wave numbers of normal modes of vibrations and various other important parameters. Calculated bond lengths and angles were compared with the experimental bond lengths and Bond Angle Parameters. Optimized bond parameters and experimental bond parameters were found in good agreement. Complete potential energy distribution assignments were done successfully by VEDA. The HOMO/LUMO energy gap emphasizes adequate charge transfer happening within the molecule. A study of donor-acceptor interconnections was done via NBO analysis. MEP surface analysis was done to demonstrate charge distribution and reactive areas qualitatively in the molecule. The degree of relative localization of electrons was analyzed via ELF Diagram. The Fukui function analysis showed possible sites for attacks by different substituents. By using the TD-DFT method and PCM solvent model, the UV-Vis spectrum (gas, methanol, DMSO) and the maximum absorption wavelength was computed and compared with experimental data. 3D and 2D intermolecular interactions in the crystal were analyzed via Hirshfeld surface analysis and fingerprint plots reveal that the EAMC crystal was stabilized by H--H/H--H/C--H bond formation. The molecular docking was done with 7 different protein receptors on the molecule to find the best ligand-protein interactions. Molecular dynamic simulations and MMGBSA calculations were also carried out to find out the best binding of the ligand with the protein.Communicated by Ramaswamy H. Sarma.

Left Coronary Artery to Pulmonary Trunk Fistula: Two Case Reports With Literature Review.

Coronary artery fistulas (CAFs) are abnormal communication between coronary arteries and the pulmonary trunk or with adjacent heart structures. Coronary pulmonary artery fistulas (CPAFs) can be congenital or acquired. Mostly, CAFs are found as incidental findings on angiographic evaluation. The management of CPAFs varies from case to case depending on size, anatomical location, patient's clinical presentation, and presence of coronary steal phenomenon. We present two cases of CPAFs; one of them had coronary steal phenomena at a young age with no past medical history of coronary artery disease, and the patient underwent transcatheter coil embolization to close the fistula. In other cases, a fistulous connection between the left anterior descending (LAD) and the pulmonary trunk was found incidentally on computed tomography (CT) of the heart and based on a small-sized fistula and symptomatic improvement, the patient was discharged with conservative management. CPAFs are rare cardiac anomalies but can give rise to severe hemodynamic complications, so this should be a part of the initial differential diagnosis if the patient does not have significant coronary artery disease. Percutaneous closure or surgical correction is indicated if the patients are symptomatic or have secondary complications.

Dynamical phenomena developed by a spiralling stretchable sheet in magnetized Casson-spinel ferrite nanofluid.

Nanofluid research has sparked widespread attention due to its immense implementations in various courses, including chemical engineering, microelectronics, solar energy, cooling systems, electronics, power-saving, etc. This research offers modelling and numerical simulation for the magnetized Casson-based spinel ferrite (MnFe2O4) nanofluid stream owing to a spiralling stretchable sheet placed in a Darcy permeable medium. Diverse impacts like nonlinear heat radiation, viscous and Joule warms, and heat generation/absorption are considered in stimulating heat exchange. Under the imposed physical assumptions, equations governing the flow and heat flow are modelled. The partial derivative model is transferred to the ordinary derivative model by utilising compatible similarity variables. The resulting nonlinear linked ordinary derivative model is tackled computationally by the 4th-order Runge-Kutta integration procedure, accomplishing the best strategy shooting algorithm based on the built-in function of the bvp4c solver in MATLAB. Different attributes of the considered flow phenomenon corresponding to the pertinent model parameters are disclosed effectively via graphs and tables. Some leading outcomes are that amplification is examined in the thermal field and allied zone thickness responding to the radiation parameter and Biot number. With the upgraded rotation parameter, an augmentation is developed in the absolute value of the local skin friction coefficients. Moreover, amplifying the rotation parameter enfeebles the local Nassault number. This modelling could be effective in manufacturing and technological processes like polymeric material extrusion, stretchable/shrinkable packaging, and designing magnetic storage devices.

Myopericarditis Following the Third Dose of COVID-19 mRNA Vaccination: A Case Report.

Coronavirus disease 2019 (COVID-19) mRNA vaccine-related cases of pericarditis and myocarditis have been reported infrequently. Most of the patients usually present within a week of the vaccine, and on average, most of the cases were reported after the second dose of vaccine within two to four days. Chest pain was the most common presentation, and fever and shortness of breath were the other commonly reported symptoms. The patients can have positive cardiac markers and electrocardiogram (EKG) changes, and the cases can be mistaken for cardiac emergencies. We present a 17-year-old male patient with sudden onset substernal chest pain for two days who got the third dose of the Pfizer-BioNTech mRNA vaccine within 24 hours prior. EKG was remarkable for diffuse ST elevations, and troponins were elevated. Later, the cardiac magnetic resonance imaging confirmed the findings of myopericarditis. The patient was treated with colchicine and non-steroidal anti-inflammatory drugs (NSAIDs), completely recovered, and is doing fine to date. This case hights that post-vaccine myocarditis can be mistaken and early diagnosis and management can prevent unnecessary interventions.

Survival outcomes for patients with nasopharyngeal carcinoma in non-endemic region in the UK treated with intensity modulated based radiotherapy 65 Gy in 30 fractions ± weekly cisplatin chemotherapy.

Background: Nasopharyngeal carcinoma (NPC) is rare in the UK. The aim of the current study was to investigate survival outcomes for patients with NPC treated with (chemo)radiotherapy using 65 Gy in 30 fractions in a non-endemic region. Materials and methods: All consecutive 62 patients with histology proven non-metastatic nasopharyngeal carcinoma diagnosed between January 2009 to June 2019 were included in this retrospective analysis. Results: Median age was 59 years (range:19-81). The majority of patients had stage III disease (66.1%). Induction chemotherapy was given in 21% of patients and 82.3% of patients received concomitant systemic therapy. All patients were treated with 65 Gy in 30 fractions. There was disease recurrence in 17.4% patients. The 5-year disease-free, disease-specific and overall survival were 81.9%, 79.2% and 76.4%, respectively. On univariate analysis, disease recurrence was associated with N-stage (p = 0.047) and overall stage group (p = 0.023). Conclusion: To the best of authors' knowledge, this is the first report of the use of 65 Gy in 30 fractions of radiotherapy ± weekly cisplatin chemotherapy in NPC in a real-world setting. Our results are comparable to that from other non-endemic regions of the world using different dose fractionation of (chemo)radiotherapy. Future randomised control trials are warranted to compare various dose fractionations in these settings.

Household COVID-19 secondary attack rate and associated determinants in Pakistan; A retrospective cohort study.

BACKGROUND: COVID-19 household transmissibility remains unclear in Pakistan. To understand the dynamics of Severe Acute Respiratory Syndrome Coronavirus disease epidemiology, this study estimated Secondary Attack Rate (SAR) among household and close contacts of index cases in Pakistan using a statistical transmission model. METHODOLOGY: A retrospective cohort study was conducted using an inclusive contact tracing dataset from the provinces of Punjab and Khyber-Pakhtunkhwa to estimate SAR. We considered the probability of an infected person transmitting the infection to close contacts regardless of residential addresses. This means that close contacts were identified irrespective of their relationship with the index case. We assessed demographic determinants of COVID-19 infectivity and transmissibility. For this purpose based on evolving evidence, and as CDC recommends fully vaccinated people get tested 5-7 days after close contact with a person with suspected or confirmed COVID-19. Therefore we followed the same procedure in the close contacts for secondary infection. FINDINGS: During the study period from 15th May 2020 to 15th Jan 2021, a total of 339 (33.9%) index cases were studied from 1000 cases initially notified. Among close contact groups (n = 739), households were identified with an assumed mean incubation period of 8.2+4.3 days and a maximum incubation period of 15 days. SAR estimated here is among the household contacts. 117 secondary cases from 739 household contacts, with SAR 11.1% (95% CI 9.0-13.6). All together (240) SAR achieved was 32.48% (95% CI; 29.12-37.87) for symptomatic and confirmed cases. The potential risk factors for SAR identified here included; old age group (>45 years of age), male (gender), household members >5, and residency in urban areas and for index cases high age group. Overall local reproductive number (R) based on the observed household contact frequencies for index/primary cases was 0.9 (95% CI 0.47-1.21) in Khyber Pakhtunkhwa and 1.3 (95% CI 0.73-1.56) in Punjab. CONCLUSIONS: SAR estimated here was high especially in the second phase of the COVID-19 pandemic in Pakistan. The results highlight the need to adopt rigorous preventive measures to cut the chain of viral transmission and prevent another wave of COVID-19.

Iron(III) Complexes of a Hexadentate Thioether-Appended 2-Aminophenol Ligand: Redox-Driven Spin State Switchover.

A green complex [Fe(L3)] (1), supported by the deprotonated form of a hexadentate noninnocent redox-active thioether-appended 2-aminophenolate ligand (H4L3 = N,N'-bis(2-hydroxy-3,5-di-tert-butylphenyl)-2,2'-diamino(diphenyldithio)ethane), has been synthesized and structurally characterized at 100(2) K and 298(2) K. In CH2Cl2, 1 displays two oxidative and a reductive one-electron redox processes at E1/2 values of -0.52 and 0.20 V, and -0.85 V versus the Fc+/Fc redox couple, respectively. The one-electron oxidized 1+ and one-electron reduced 1- forms, isolated as a blackish-blue solid 1(PF6)·CH2Cl2 (2) and a gray solid [Co(η5-C5H5)2]1·DMF (3), have been structurally characterized at 100(2) K. Structural parameters at 100 K of the ligand backbone and metrical oxidation state values unambiguously establish the electronic states as [FeIII{(LAPO,N)2-}{(LISQO,N)•-}{(LS,S)0}] (1) (two tridentate halves are electronically asymmetric-ligand mixed-valency), [FeIII{(LISQO,N)•-}{(LISQO,N)•-}{(LS,S)0}]+ (1+), and [FeIII{(LAPO,N)2-}{(LAPO,N)2-}{(LS,S)0}]- (1-) [dianionic 2-amidophenolate(2-) (LAPO,N)2- and monoanionic 2-iminobenzosemiquinonate(1-) π-radical (Srad = 1/2) (LISQ)•- redox level]. Mössbauer spectral data of 1 at 295, 200, and 80 K reveal that it has a major low-spin (ls)-Fe(III) and a minor ls-Fe(II) component (redox isomers), and at 7 K, the major component exists exclusively. Thus, in 1, the occurrence of a thermally driven valence-tautomeric (VT) equilibrium (asymmetric) [FeIII{(LAPO,N)2-}{(LISQO,N)•-}{(LS,S)0}] ⇌ (symmetric) [FeII{(LISQO,N)•-}{(LISQO,N)•-}{(LS,S)0}] (80-295 K) is implicated. Mössbauer spectral parameters unequivocally establish that 1+ is a ls-Fe(III) complex. In contrast, the monoanion 1- contains a high-spin (hs)-Fe(III) center (SFe = 5/2), as is deduced from its Mössbauer and EPR spectra. Complexes 1-3 possess total spin ground states St = 0, 1/2, and 5/2, respectively, based on 1H NMR and EPR spectra, the variable-temperature (2-300 K) magnetic behavior of 2, and the µeff value of 3 at 300 K. Broken-symmetry density functional theory (DFT) calculations at the B3LYP-level of theory reveal that the unpaired electron in 1+/2 is due to the (LISQ)•- redox level [ls-Fe(III) (SFe = 1/2) is strongly antiferromagnetically coupled to one of the (LISQ)•- radicals (Srad = 1/2)], and 1-/3 is a hs-Fe(III) complex, supported by (L3)4- with two-halves in the (LAP)2- redox level. Complex 1 can have either a symmetric or asymmetric electronic state. As per DFT calculation, the former state is stabilized by -3.9 kcal/mol over the latter (DFT usually stabilizes electronically symmetric structure). Time-dependent (TD)-DFT calculations shed light on the origin of observed UV-vis-NIR spectral absorptions for 1-3 and corroborate the results of spectroelectrochemical experiments (300-1100 nm) on 1 (CH2Cl2; 298 K). Variable-temperature (218-298 K; CH2Cl2) absorption spectral (400-1000 nm) studies on 1 justify the presence of VT equilibrium in the solution-state.

Prevalence and Associated Factors of Depression among Patients with HIV/AIDS in Lahore, Pakistan: Cross-Sectional Study.

BACKGROUND: Depression is defined as a psychiatric disorder characterized by depressed mood, lack of concentration, diminished energy, disturbed sleep, and low self-esteem. Depression is more prevalent in HIV/AIDS patients than the general population. There is no published study available that reveals the present status of depression among HIV patients in Pakistan. As such, the present study was conducted to determine the prevalence and associated factors of depression among HIV/AIDS patients attending the HIV clinic of Jinnah Hospital, Lahore, Pakistan. METHODS: A hospital-based cross-sectional study was carried out from February to March 2019 in Lahore. Data were collected from 158 HIV/AIDS patients using a pretested, standardized, structured interviewer-administered questionnaire. Nonprobability convenience sampling was used to recruit the study participants. Depression was evaluated using the Patient Health Questionnaire. SPSS version 23 was used to analyze the data. Binary logistic regression models were used to determine the various factors associated with depression. AORs with 95% CIs were used to assess the magnitude of associations between depression and associated factors. RESULTS: The mean age of the study participants was 35.03 years±9.123. Prevalence of depression among HIV/AIDS patients was 32.2%. Living in a rural area (AOR 5.60, 95% CI 2.20, 14.15), fear of stigma and discrimination (AOR 3.505, 95% CI 1.364, 9.008), having worked abroad (AOR 3.017, 95% CI 1.134, 8.031), and history of substance abuse (AOR 4.147, 95% CI 1.673, 10.28) were significantly associated with depression. CONCLUSION: The prevalence of depression among HIV/AIDS patients is very high in Pakistan. Therefore, it is suggested that guidelines formulated to screen and treat depression among HIV patients.

Guided tooth preparation device fabricated with a complete digital workflow: A dental technique.

Guided tooth preparations allow clinicians to provide fixed dental prostheses for dentate patients in an efficient manner. One approach uses a digital preparation device technique where the preparation of a tooth needing a crown is guided by a device. Compared with conventional techniques, this method allows for accurate abutment preparation more efficiently and with improved quality. By controlling tooth preparation, this method preserves natural tooth structure and provides adequate clearance for the restorative material. To illustrate this technique, an adhesive minimally invasive fixed complete-mouth rehabilitation was provided by using a 3D-printed digital preparation device.

Molecular epidemiology and genotype distribution of hepatitis C in Pakistan; a multicenter cross-sectional study.

Pakistan has second highest burden of hepatitis C virus (HCV) infected patients in the World. Little is known about the molecular epidemiology and risk factors for prevailing HCV genotypes in Pakistan. Considering this a multicenter cross-sectional study was conducted at 23different viral hepatitis control and prevention centers. A total of 175,897 patients were registered and screened for HCV, out of which 73,180 (41.6%) were found positive on Architect screening test. The screened positive patients were sequentially tested on RT-PCR; where 41,241 (56.35%) were detected positive. Molecular characterization results showed genotype 3 (73.9%) as the most prevalent type, followed by genotype 1 (9.7%), and genotype 4 (0.3%) was isolated for the first time in Pakistan. On regression analysis; risk factors associated with genotype 3 and 1 included; age group of 30-50 years, rural residence, exposure to >10 injections, barber shaving, circumcision by barbers, and low literacy rate. Phylogenetic analysis based on genotypes identified in this study and sequences isolated from Pakistan in last 10 years demonstrated that genotype 3 and 1 are endemic locally in Punjab province. The high prevalence rate of HCV is a threat for a generalized epidemic and genetic recombination with such variability of genotypes identified here is an alarming condition. More focused attention and resources should be spent in awareness of the population to prevent the spread of HCV among high risk population.

Abiraterone acetate plus Prednisone/Prednisolone compared with Enzalutamide in metastatic castration resistant prostate cancer before or after chemotherapy: A retrospective study of real-world data (ACES).

Background: Abiraterone acetate combined with Prednisone/Prednisolone (AA+P) and Enzalutamide (ENZ) have proven survival benefit in men with metastatic castration-resistant prostate cancer (mCRPC) in chemotherapy-naïve and prior chemotherapy patients. There have been no studies directly comparing the effectiveness of ENZ to AA+P in mCRPC patients. Methods: A retrospective, survival analysis study of 143 real-world mCRPC patients (90 in AA+P and 53 in ENZ group) was conducted. Patients who started their treatment between February 2012 and May 2016 were included. The primary end point was biochemical progression-free survival (bPFS). Secondary end points were radiological progression-free survival (rPFS) and overall survival (OS). Toxicity data were also collected. Data were analyzed using Cox proportional hazards (PH) models, adjusting for covariates: prior radical treatment; Gleason score; prostate-specific antigen; age; and chemotherapy naïve or not. Results: After median follow-up of 15 months (interquartile range 7 to 23), 112 events of biochemical progression were observed (71 in AA+P and 41 in ENZ). About 41% in AA+P group and 30% patients in ENZ group received prior chemotherapy. The chance of biochemical progression was significantly lower among ENZ patients than AA+P patients, when adjusting for all covariates in the Cox PH model (hazard ratio [HR] 0.54, 95% confidence interval [CI] 0.35 to 0.82, P = .004). There was a trend implying the chance of rPFS could be higher among ENZ patients than AA+P patients (HR 1.24, 95% CI 0.76 to 2.02, P = .4). There is no difference in OS between ENZ and AA+P patients, when adjusting for all covariates in the Cox PH model (HR 0.91, 95% CI 0.59 to 1.41, P = .7). About 38% of ENZ patients reported fatigue compared to 16% of AA+P patients, while hypertension was reported slightly more in AA+P patients. Conclusions: This study showed a statistically significant difference in bPFS, favoring ENZ, but no significant difference in rPFS or OS.

Recent applications of Rose Bengal catalysis in N-heterocycles: a short review.

The visible light harnessing ability of Rose Bengal, an organic dye, has been extensively employed in organic chemistry over the last few years. In visible light mediated reactions, this photoredox catalyst operates through multiple pathways and has the ability to provide distinctly different and valuable results. The most significant of these results are bond creation, bond functionalization, particularly for C-H and C-heteroatom bonds, and cross couplings. It is crucial to study these cases whenever these bond formations and couplings lead to the formation of heterocyclic compounds or their functionalization. The diverse biological activity and medicinal applications of heterocyclic compounds is an extensively explored area. This review primarily attempts to demonstrate the synthetic potential of Rose Bengal for synthesis and site selective functionalization of nitrogen containing heterocycles.

Immediately loaded interim complete-arch implant-supported fixed dental prostheses fabricated with a completely digital workflow: A clinical technique.

A digital method for delivering an immediately loaded interim complete-arch implant-supported prosthesis is described. Reference pins were used to accurately superimpose a postoperative scan with the scan bodies in place on a preoperative scan with the framework design, including the interocclusal relationship and the occlusal scheme. A prefabricated auxiliary device was used after surgery to record the position of the implants and after scanning to obtain an accurate transfer of the implant positions by means of a free software program, allowing an excellent fit of the fabricated prosthesis. This technique can help in the fabrication of an interim prosthesis with better fit and comfort and reduced chair time than conventional techniques.

Elemental: An Open-Source Wireless Hardware and Software Platform for Building Energy and Indoor Environmental Monitoring and Control.

This work demonstrates an open-source hardware and software platform for monitoring the performance of buildings, called Elemental, that is designed to provide data on indoor environmental quality, energy usage, HVAC operation, and other factors to its users. It combines: (i) custom printed circuit boards (PCBs) with RFM69 frequency shift keying (FSK) radio frequency (RF) transceivers for wireless sensors, control nodes, and USB gateway, (ii) a Raspberry Pi 3B with custom firmware acting as either a centralized or distributed backhaul, and (iii) a custom dockerized application for the backend called Brood that serves as the director software managing message brokering via Message Queuing Telemetry Transport (MQTT) protocol using VerneMQ, database storage using InfluxDB, and data visualization using Grafana. The platform is built around the idea of a private, secure, and open technology for the built environment. Among its many applications, the platform allows occupants to investigate anomalies in energy usage, environmental quality, and thermal performance via a comprehensive dashboard with rich querying capabilities. It also includes multiple frontends to view and analyze building activity data, which can be used directly in building controls or to provide recommendations on how to increase operational efficiency or improve operating conditions. Here, we demonstrate three distinct applications of the Elemental platform, including: (1) deployment in a research lab for long-term data collection and automated analysis, (2) use as a full-home energy and environmental monitoring solution, and (3) fault and anomaly detection and diagnostics of individual building systems at the zone-level. Through these applications we demonstrate that the platform allows easy and virtually unlimited datalogging, monitoring, and analysis of real-time sensor data with low setup costs. Low-power sensor nodes placed in abundance in a building can also provide precise and immediate fault-detection, allowing for tuning equipment for more efficient operation and faster maintenance during the lifetime of the building.

Crystal structure of 4-[(3-meth-oxy-2-oxidobenzyl-idene)azaniumyl]-benzoic acid methanol monosolvate.

In the crystal of the title compound, C15H13NO4·CH3OH, the Schiff base mol-ecule exists in the zwitterionic form; an intra-molecular N-H⋯O hydrogen bond stabilizes the mol-ecular structure. The benzene rings are nearly co-planar, subtending a dihedral angle of 5.34 (2)°. In the crystal, classical O-H⋯O and weak C-H⋯O hydrogen bonds link the Schiff base mol-ecules and methanol solvent mol-ecules into a three-dimensional supra-molecular architecture. The crystal studied was refined as an inversion twin.

Comparison of postoperative pain after root canal treatment using reciprocating instruments based on operator's experience: A prospective clinical study.

BACKGROUND: The aim of the present study was to compare clinically the incidence of postoperative pain after endodontic treatment using the Reciproc System, taking into account the operator's experience. MATERIAL AND METHODS: One hundred patients scheduled for routine endodontic treatment were enrolled in this study. Endodontic treatment was carried out in a single visit by undergraduate and postgraduate students. The chemomechanical preparation of root canals was performed with Reciproc instruments. Pretreatment and postoperative pain was recorded using a visual analogue scale (VAS). Postoperative pain and the need for analgesic consumption were assessed at 4, 8, 16, 24, 48 and 72 hours post-treatment. The data were analyzed using the Mann-Whitney U and Chi-Square test, and the significance was set at P<0.05. RESULTS: The mean value of pain after root canal treatment was 1.13±1.94 and 1.91±2.07 on a VAS between 0 and 10 in treatments performed by undergraduate and postgraduate students, respectively. There was a significant difference in the incidence of postoperative pain between the two groups (P<0.05). CONCLUSIONS: The prevalence of postoperative pain was high in the treatments performed by postgraduate students in comparison with undergraduate students. This suggests that operator experience has an influence on the prevalence of postoperative pain after root canal treatment. Key words:Post-endodontic pain, root canal treatment, reciprocating systems, Expert operators Inexperienced operators.

Crystal structure of (2,2'-bi-pyridine-κ2N,N')bis-(3,5-di-tert-butyl-o-benzo-quinonato-κ2O,O')ruthenium(II).

In the title mononuclear complex, [Ru(C14H20O2)2(C10H8N2)], the RuII ion has a distorted octa-hedral coordination environment defined by two N atoms of the chelating 2,2'-bi-pyridine ligand and four O atoms from two 3,5-di-tert-butyl-o-benzo-quinone ligands. In the crystal, the complex mol-ecules are linked by inter-molecular C-H⋯O hydrogen bonds and π-π stacking inter-actions between the 2,2'-bi-pyridine ligands [centroid-centroid distance = 3.538 (3) Å], resulting in a layer structure extending parallel to the ab plane.

Crystal structure of 9,9'-{(1E,1'E)-[1,4-phenyl-enebis(aza-nylyl-idene)]bis-(methanylyl-idene)}bis-(2,3,6,7-tetra-hydro-1H,5H-pyrido[3,2,1-ij]quinolin-8-ol).

The whole mol-ecule of the title compound, C32H34N2O2, is generated by inversion symmetry; the central benzene ring being situated about the crystallographic inversion center. The aromatic ring of the julolidine moiety is inclined to the central benzene ring by 33.70 (12)°. There are two intra-molecular O-H⋯N hydrogen bonds in the mol-ecule, generating S(6) ring motifs. The conformation about the C=N bonds is E. The fused non-aromatic rings of the julolidine moiety adopt half-chair conformations. In the crystal, adjacent mol-ecules are linked by pairs of C-H⋯π inter-actions, forming a ladder-like structure propagating along the a-axis direction.