Single Root Research Articles

Ability of laser in removing gutta percha from root canal using chloroform and endosolv

Background: Residual necrotic tissue or bacteria beneath gutta percha or sealer can be responsible for periapical inflammation or pain. The present study was conducted to the ability of laser in removing gutta percha from root canal using chloroform and Endosolv E. Materials & Methods: 60 freshly extracted permanent human maxillary central incisors with single and straight root canals were divided into 3 groups based on retreatment method used: group I- only diode laser; group II- diode laser along with chloroform as solvent and group III- diode laser along with Endosolv E as solvent. After completion of retreatment, roots were sectioned longitudinally and viewed under stereomicroscope at 10X magnification. The area of the remaining filling material in each half was measured. Results: The mean percentage area of remaining root canal filling material in group I was 18.2, in group II was 11.7 and in group III was 14.3. The difference was significant (P< 0.05). Conclusion: Diode laser with chloroform and diode laser with Endosolv E were significantly more effective than only diode laser in the removal of gutta-percha from the root canal.

Grazing promoted plant litter decomposition and nutrient release: A meta-analysis

Grazing considerably affects ecosystem nutrient cycling and element stoichiometry at the regional and global levels according to synthesized studies. However, the effects of grazing, especially its intensity, on the plant litter decomposition stage of key processes in biogeochemical cycles are not clearly understood. Here, a meta-analysis of 65 published papers was undertaken to examine the responses of eight variables associated with litter decomposition to grazing or grazing intensity. We also explored whether experimental and environmental factors altered the effects of grazing on litter decomposition. Our results indicated that grazing significantly promoted litter decomposition when all the data was averaged, and that the magnitude of its effects on litter decomposition became weaker as grazing intensity increased. Grazing did not affect mixed root litter decomposition, but increased single root litter decomposition, and light grazing had a stronger positive effect. Specifically, grazing significantly accelerated litter C and P release, and significantly increased single N release by single above-ground litter, but not root or mixed aboveground litter. In addition, environmental factors (e.g., elevation, and mean annual precipitation) and experimental factors (e.g., experiment duration and litterbag size) affected the litter decomposition responses to grazing. These results suggest that the effects of grazing on litter decomposition and nutrient release depend on grazing intensity, litter type, and plant organs. Grazing alters terrestrial plant litter decomposition and grazing intensity plays an important role in regulating the magnitude of the effect during litter decomposition and nutrient cycling.

A taxonomy of simulated geomagnetic jerks

SUMMARYGeomagnetic jerks—abrupt changes in the acceleration of Earth’s magnetic field that punctuate geomagnetic records— have been richly documented over the past decades by taking advantage of the complementary strengths of ground observatory and satellite measurements. It has recently been proposed that these events originate from the interplay and timescale separation between slow convection and rapid hydromagnetic wave propagation in Earth’s outer core, with these latter waves playing a key role in the generation of jerk signals. To assess the generality of this explanation, here we analyse a catalogue of 14 events obtained during a 14 000-yr-long temporal sequence from a numerical geodynamo simulation that is the closest to date to Earth’s core conditions regarding timescale separation. Events are classified according to their dynamic origin and the depth at which they are triggered in the outer core. The majority of jerk events are found to arise from intermittent local disruptions of the leading-order force balance between the pressure, Coriolis, buoyancy and Lorentz forces (the QG-MAC balance), that leads to an inertial compensation through the emission of rapid, non-axisymmetric, quasi-geostrophic Alfvén waves from the region where this force balance is disrupted. Jerk events of moderate strength arise from the arrival at low latitudes at the core surface of hydromagnetic wave packets emitted from convective plumes rooted at the inner core boundary. As in an earlier simulation, these account well for jerk features that have recently been documented by satellite and ground observations. The more realistic timescales in the simulation reported here allow further details to be distinguished, such as multiple temporal alternations of geomagnetic acceleration pulses at low latitudes, long-range synchronization of pulse foci in space and rapid longitudinal drift of these foci at the core surface. The strongest events in the catalogue arise from disruption of the leading-order force balance near or at the core surface, from the combined influence of the arrival of buoyancy plumes and magnetic field rearrangement. The hydromagnetic waves that are sent laterally and downwards generate signals that clearly illustrate the presence of nearly synchronous ‘V-shaped’ magnetic variation patterns over a wide portion of Earth’s surface and also at mid to high latitudes, despite the source being confined to low latitudes at the core surface. Other well-known characteristics of strong geomagnetic jerks such as surges in the intensity of the secular variation and inflexions in the length-of-day variations are also reproduced in these events. Irrespectively of the event strength, our results support the hypothesis of a single physical root cause—the emission of magneto-inertial waves following a disruption of the QG-MAC balance—for jerks observed throughout the geomagnetic record.

A novel three-dimensional quantitative assessment method for abnormal root morphology of the maxillary premolars in vivo on cone-beam computed tomography

BackgroundPrevious studies have described and recorded abnormal root morphology; however, most of these studies were based on two-dimensional periapical or panoramic radiographs, and only a few studies have quantified it. We aimed to combine two-dimensional periapical radiographs and three-dimensional cone-beam computed tomography (CBCT) to conduct qualitative judgments and quantitative analyses of normal and conical roots, and explore the clinical diagnostic method of normal and conical roots based on intraoral radiographs and CBCT.MethodsThe conical root was identified visually on periapical radiographs as the clinical gold standard. All teeth were divided into the cone-rooted teeth (CRT) or normal-rooted teeth (NRT) groups. Furthermore, differences in root length (RL), root surface area (RSA), and root volume (RV) of conical and normal roots in the maxillary premolars on CBCT were compared. Receiver operator characteristic curves were generated, and the area under the curve (AUC) and cut-off values were calculated to evaluate the diagnostic value of RV, RSA, RV/RL, and RSA/RL.ResultsThe RSAs of NRT and CRT were 236.88 ± 27.93 mm2 and 207.98 ± 27.80 mm2, respectively (P = 0.000). The mean RV in the CRT group was lower than that in the NRT group, and the difference was statistically significant (253.40 ± 41.98 mm3 vs. 316.93 ± 49.89 mm3, P = 0.000). The RSA and RV of conical roots in single root premolars were 12.29% and 19.33% less than those of normal roots, respectively. The AUC values of RSA/RL and RV/RL were 0.87 and 0.89, respectively, and the best cut-off values were 19.61 for RSA/RL (if RSA/RL was < 19.61, the teeth were considered CRT) and 24.05 for RV/RL (if RV/RL was < 24.05, the teeth were considered CRT).ConclusionsCBCT has significant diagnostic value in the clinical evaluation of conical roots. RSA/RL and RV/RL were the best parameters with the largest AUC and high sensitivity and specificity.

Surgical management of sacral neurogenic tumors

To observe the efficacy and complications of one-stage tumor resection to treat primary sacral neurogenic tumors and to discuss some details in the clinically relevant anatomy. A retrospective analysis of 26 patients with neurogenic turors of the sacral spine who were surgically treated from January 2001 to January 2018, including 16 males and 10 females, aged from 21 to 69 years old with an average age of (39.3±10.9) years old. The courses of diseases ranged from 3 to 56 months with an average of (17.9±10.1) months. The diameters of presacral components ranged from 3.3 to 19.6 cm with an average of (8.7±4.1) cm. The proximal margin of presacral lesions was above the L5S1 level in 6 cases, and lower than L5S1 in 20 cases. A posterior incision approach for one-stage complete resection of the tumor was used firstly, and an anterior approach was combined when necessary. Spinal-pelvic reconstruction with the modified Galveston technique was also carried out in relevant cases. Whether to preserve the tumor-involved nerve roots depended on the situation during the operation. The operation time, intraoperative blood loss, pain relief, and complications were recorded. The lumbosacral spine stability and sacral plexus neurological function were evaluated during postoperative follow-up, and local recurrence and distant metastasis were examined as well. Total excision was achieved in all 26 patients, with an operation time of (160.4±35.3) mins and an intraoperative blood loss of (1 092.3±568.8) ml. Tumors have been removed via a posterior-only approach in 21 cases and via combined anterior/posterior approaches in 5 cases. The diameter of presacral masses components ranged from 11.3 to 19.6 cm with an average of (15.1±3.2) cm in patients with combined anterior/posterior approaches, and ranged from 3.3 to 10.9 cm with an average of (7.2±2.4) cm in patients with a posterior-only approach. Five of the six patients whose proximal margin of presacral masses was above the L5S1 level adopted combined anterior/posterior approaches, and 20 patients lower than the L5S1 level adopted the posterior-only approach. All the patients were followed up for 6 to 82 months with an average of(45.4±18.2)months. Postoperative lumbosacral pain and lower extremity radicular pain were significantly relieved, and sensation, muscle strength and bowel and bladder function were also improved to varying degrees. The postoperative early complications included superficial wound infection in 1 case and cerebrospinal fluid leakage in 2 cases. Pathology confirmed 17 cases of schwannoma, 7 cases of neurofibroma and 2 cases of malignant schwannoma. Local recurrence was observed in two cases of benign neurogenic tumors. One patient with a malignant nerve sheath tumor had lung metastasis, who died 20 months after the operation. In 17 cases of upper sacral neurogenic tumors, 4 cases did not undergo spinal-pelvic reconstruction with internal fixation, of which 2 cases suffered from postoperative segmental instability. Tumor-involved nerve roots were resected during surgery in 7 cases. One of these patients who had S2 and S3 nerve roots sacrificed simultaneously had an impaired bladder and bowel function postoperatively, and did not recover completely. In the other 6 cases, the neurological function was not damaged obviously or recovered well. The posterior approach can directly expose the lesions, and it is also convenient to deal with nerve roots and blood vessels. The operation time, intraoperative blood loss, degree of symptom relief, complication rate, and recurrence and metastasis rate can be controlled at an appropriate level. It is a safe and effective surgical approach. When the upper edge of the presacral mass is higher than the L5S1 level or the diameter of the presacral mass exceeds 10 cm, an additional anterior approach should be considered. The stress between the spine and pelvis is high, and internal fixation should be used to restore the mechanical continuity of the spine and pelvis during resection of neurogenic tumors of the high sacral spine. Most of the parent nerve roots have lost their function. Resection of a single parent nerve root is unlikely to cause severe neurological dysfunction, while the adjacent nerve roots have compensatory functions and should be preserved as much as possible during surgery.

In-vitro study quantitative evaluation of apically extruded debris during canal preparation using three different motions of hand files

This study aimed to evaluate the quantity of apically extruded debris during the bio-mechanical preparation of the root canal treatment. Fifteen extracted premolars with single root canal were collected and divided into three groups for this study. Hand protaper files (reaming motion), K files (watch-wind motion), and K flex files (balanced force technique) were used. The irrigant and debris were collected in pre-weighed (using analytic scale) empty microtainer bottles. The microtainers were kept in an incubator at 700C for 4 days for complete drying and then weighed of dry debris was recorded. Statistical analysis: Data was treated for the mean values of the weight and analysed using kruskall-wallis test at a significance of 0.05. All the three motions of hand files extruded debris. Watch wind motion showed the lowest mean value whereas reaming showed the highest. There were no significant difference between the reaming motion, watch wind motion and balanced force technique (p &lt;0.05). The study revealed that the amount of extruded debris from the apical foramen was comparatively least in watch wind motion among all the three motions in terms of the mean weight but there is no significance difference between the three Groups.

Root canal narrowing patterns of mandibular first premolars on panoramic radiographs according to the number of root canals diagnosed on cone beam computed tomographic images.

Understanding the variations in root canal morphology is important for successful endodontic treatment. Mandibular first premolars have a single root in 98% of cases, and multiple root canals are found in approximately 20% of cases. However, the details of these characteristic findings in panoramic radiography and their diagnostic accuracy are unknown. This study aimed to investigate the characteristic radiographic findings of mandibular first premolars possessing multiple root canals and determine the diagnostic accuracy using panoramic radiography. Four radiologists evaluated 347 mandibular first premolars in 186 patients who underwent panoramic radiography and dental cone beam computed tomography (CBCT). Two radiologists confirmed the existence of single or multiple root canals using CBCT. The remaining two radiologists evaluated the imaging findings of the root canal morphology and classified them into two patterns: gradual narrowing and sudden narrowing. In the case of the sudden narrowing pattern, the location of sudden narrowing was also evaluated. A gradual narrowing pattern was observed in 56% of teeth with a single root canal, and a sudden narrowing pattern was observed in 83% of teeth with multiple root canals. When sudden narrowing between the cervical and apical 1/4 of the root canal was used as the diagnostic criterion for multiple root canal teeth, the highest diagnostic performance was observed (sensitivity, 76.1%; specificity, 73.9%). The sudden narrowing between the cervical level and the apical 1/4 level of the root canal is a practical diagnostic criterion for mandibular first premolar with multiple root canals.

Selective Spinal Nerve Root Block as an efficacious modality of treatment in lower backache with radiculopathy in cases of single level prolapsed intervertebral disc

Background: Back pain affects everybody at some point in their life and is one of the most common complaints evaluated by a spine surgeon. Lower limb radiculopathy is commonly associated with conditions like disc herniation, facet or ligamentous hypertrophy, and spondylolisthesis. The present study was conducted to assess the prognosis after a single dose of Selective Spinal Nerve Root Block in patients with lower backache with radiculopathy with a single level disc prolapse. Methods:Forty patients with complaints of lower backache with lower limb radiculopathy with a single level Prolapse Intervertebral disc[Magnetic Resonance Imaging (MRI) diagnosed] were assessed on the basis of Visual Analogue Scale score and Roland Morris Questionnaire score at different time intervals pre and post single level spinal nerve root block to assess the reduction in pain. Results:Pain recurrence was noted in four (10%) patients at 3-month post block and total five patients at six months post block. Five (12.5%) patients underwent a surgical procedure after six months of a block. A significant (p&lt;0.0001) reduction in the Roland Morris Questionnaire scores (Mean 19.53) and Visual Analogue Scale score for back pain (Mean 4.48) and leg pain (Mean 7.5) were observed during the follow-ups of Roland Morris Questionnaire scores at three months (Mean 2.55) and six months (Mean 3.55); with Visual Analogue Scale score at three months for back pain (Mean 1.60), leg pain (Mean 1.45) and six months for back pain (Mean 1.07) and leg pain (Mean 2.2) in 35 (87.5%) study subjects after block. Conclusion: The study recorded a pain-free period averaging six months with positive outcomes in almost all patients, indicating selective nerve root block efficacy among patients with lower back pain with radiculopathy with a single level prolapsed intervertebral disc, especially in younger patients and those with a short duration of symptoms.

Paper 17: Optimal Tibial Tunnel Placement for Medial and Lateral Meniscal Root Repair in the Setting of Multiligament Reconstructions of the Knee

Objectives:Although the risk of tibial tunnel convergence in the setting of multiligament reconstruction has been reported in the literature, the risk of tunnel convergence in the setting of posterior cruciate ligament (PCL), anterior cruciate ligament (ACL), and medial and lateral meniscal root repair has not been defined. The purpose of this study was to examine the risk of tunnel convergence and to determine optimal tunnel placement for ACL and PCL reconstruction performed in conjunction with posterior medial and lateral meniscal root repairs in the proximal tibia.Methods:Three-dimensional tibial models were created using computed tomography scans of twenty cadaveric specimens. After determining optimal tunnel entry and exit points for ACL and PCL reconstructions, and medial and lateral meniscal root repair on the models, Mimics software was used to create root tunnels. The meniscal root repair tunnels were then re-oriented to be parallel to the ACL tunnel. The initial and re-oriented configurations are illustrated in Figure 1. Tunnel convergence risk was analyzed with single and double tunnel techniques in both case scenarios.Results:There were no cases of convergence between the ACL and medial meniscal root tunnels in any of the configurations. The greatest distance between the tunnels was achieved with the single tunnel technique in parallel orientation (12.09 ± 2.78 mm). All specimens demonstrated convergence between the ACL and lateral meniscal root tunnels when the sagittal plane entry was not taken into consideration and only the anatomic root attachment was accounted for, for single and double tunnel techniques, but no convergence was seen between these tunnels with the parallel orientation in the sagittal plane. Figure 2 illustrates the reduction in the convergence risk when the meniscal root tunnels are reoriented as parallel to the ACL tunnel. There were no cases of convergence between the PCL and medial meniscal root tunnels in the original orientation, but 2/20 specimens demonstrated convergence in the parallel orientation with the double tunnel technique and no cases of convergence in the single tunnel technique. The PCL and lateral meniscal root tunnels did not demonstrate convergence in any configuration. Table 1 demonstrates the mean, minimum and maximum distances of each tunnel configuration as well as the number of cases where the distance between tunnels was <2mm. A summary of the preferred tunnel configurations for each setting, ranked by greatest tunnel distance conferred and cases of convergence, is reported in Table 2.Conclusions:There is a high risk of convergence between ACL and posterior meniscus root tunnels. Re-orienting meniscal root tunnels parallel to ACL tunnels may help reduce this risk. When PCL reconstruction is performed with ACL reconstruction and medial and lateral meniscal root repair, the single tunnel root repair technique may pose less risk over the double tunnel technique to prevent tunnel convergence between the meniscal root repair and PCL tunnels in the tibia.Figure 1. Illustration of the reconstruction of the tunnels. (A) Initial orientation where the meniscal root tunnels’ entry points on the anteromedial aspect of the tibia were created above the ACL tunnel. (B) The meniscal root tunnels re-orientated and were placed parallel to that of the ACL and aimed to exit at the anatomic attachment of the posterior roots of the meniscus. (Gold guide for the creation of the ACL tunnel and silver guide for the creation of the meniscal root tunnel)

Isolation Intervals of the Real Roots of the Parametric Cubic Equation and Improved Complete Root Classification

AbstractThe isolation intervals of the real roots of the real symbolic monic cubic polynomial are found in terms of simple functions of the coefficients of the polynomial (such as , , , , when is negative), and the roots of some auxiliary quadratic equations whose coefficients are also simple functions of the coefficients of the cubic. A much‐improved complete root classification, addressing the signs (together with giving the isolation intervals) of the individual roots, is also presented. No numerical approximations or root finding techniques are used. Instead of considering the discriminant of the cubic, criterion for the existence of a single real root or three real roots is found as conditions on the coefficients of the cubic, resulting from the roots of the auxiliary quadratic equations. It is also shown that, if a cubic equation has three real roots, then these lie in an interval such that , independent of . A detailed algorithm for applying the method for isolation of the roots of the cubic is also given and it is illustrated through examples, including the full mathematical analysis of the cubic equation associated with the Rayleigh elastic waves and finding the isolation intervals of its real roots.

Diagnostic evaluation and educational intervention for learning disabilities

Learning disabilities (LD), also known as learning disorders, refers to cases in which an individual experiences lower academic ability as compared to the normal range of intelligence, visual or hearing impairment, or an inability to peform learning. Children and adolescents with learning disabilities often have emotional or behavioral problems or co-existing conditions, including depression, anxiety disorders, difficulties with peer relationships, family conflicts, and low self-esteem. In most cases, attention deficit and hyperactivity disorder coexists. As learning disabilities have the characteristics of a difficult heterogeneous disease group that cannot be attributed to a single root cause, they are diagnosed based on an interdisciplinary approach through medicine and education, such as mental health medicine, education, psychology, special education, and neurology. In addition, for the accurate diagnosis and treatment of learning disabilities, the diagnosis, prescription, treatment, and educational intervention should be conducted in cooperation with doctors, teachers, and psychologists. The treatment of learning disabilities requires a multimodal approach, including medical and educational intervention. It is suggested that educational interventions such as the Individualized Education Plan (IEP) and the Response to Invention (RTI) should be implemented.

Effects of different farming systems and crop protection strategies on the health status and yield of carrots Daucus carota L. ssp. sativus

The aim of this study was to evaluate the effects of farming systems on the health status of carrots cv. Koral and root yield components. The organic farming system promoted the spread of damping-off of seedlings in the first two wet growing seasons and Alternaria leaf blight in the last growing season with normal precipitation levels. At harvest, the severity of root diseases was low. During storage, carrot roots were susceptible to soft rot, Sclerotinia rot and dry rot. In the integrated farming system, the symptoms of mixed rot were more observed at harvest and after storage, and of dry rot after storage. In the organic farming system, the symptoms of dry rot were more noted at harvest, and the symptoms of crater rot were more observed after storage. During storage, the applied crop protection methods significantly suppressed mixed rot in the integrated farming system, and dry rot in the organic system. The isolation of potential pathogens from carrot petioles and roots confirmed their participation in the disease process. Negative correlations were found between the severity of Alternaria leaf blight vs. the marketable yield of carrots and single root weight in both production systems in selected years of the study.

The Accuracy of Post and Core Fabricated with Digital Technology.

To compare the accuracy of post and cores created with three different fabricating techniques: direct conventional, machine milling, and three-dimensional (3D) printing. Thirteen extracted single root central incisors were selected. Root canal treatment and tooth preparation for crown were performed on all teeth. Post space preparation of 11 mm was created using prefabricated fiber post drill to standardize post space width and length. Root canal impressions were performed on all teeth using polyvinyl siloxane impression material. Each impression was then three dimensionally scanned using an extraoral lab scanner. The scanned impressions were used to design digital files of post and cores with 3Shape CAD software. The digitally designed post and cores were used to fabricate 3D printed and milled post and core resin patterns. The same teeth were used to fabricate post and core with conventional technique (direct duplication of root canal with resin pattern). All posts were then scanned before being invested and then cast using base metal educational alloy. The metal post and cores were tried in with sample teeth and manually adjusted until found to be clinically acceptable. The post and cores were scanned in different stages to perform digital volume measurement using Geomagic Control software to determine accuracy. Pairwise comparisons were accomplished using exact version of the sign test (α = 0.05). These three techniques of post and core fabrication showed different results in the various stages of fabrication. The accuracy of 3D printed resin pattern (26.89 ±11.09 mm3 ) was found to be inferior compare to milled resin pattern (28.20 ±11.41 mm3 , p = 0.0002). However, dimensional stability of the 3D printed resin pattern before and after casting (0.56 ±0.95 mm3 ) was found to be superior to milled resin pattern (0.79 ±0.89 mm3 ) and direct resin pattern (2.51 ±1.38 mm3 , p = 0.00002). All three techniques showed significant volume reduction after adjustment (p = 0.0002). In the final stage, the adjusted metal post and core fabricated with three different techniques showed no statistical different in accuracy (p = 0.15). Digitally fabricated post and cores have the same degree of accuracy as those fabricated using the gold standard direct conventional post and core technique.

Vascular function of the T3/modern clade WUSCHEL-Related HOMEOBOX transcription factor genes predate apical meristem-maintenance function

BackgroundPlants have the lifelong ability to generate new organs due to the persistent functioning of stem cells. In seed plants, groups of stem cells are housed in the shoot apical meristem (SAM), root apical meristem (RAM), and vascular cambium (VC). In ferns, a single shoot stem cell, the apical cell, is located in the SAM, whereas each root initiates from a single shoot-derived root initial. WUSCHEL-RELATED HOMEOBOX (WOX) family transcription factors play important roles to maintain stem-cell identity. WOX genes are grouped phylogenetically into three clades. The T3WOX/modern clade has expanded greatly in angiosperms, with members functioning in multiple meristems and complex developmental programs. The model fern Ceratopteris richardii has only one well-supported T3WOX/modern WOX gene, CrWUL. Its orthologs in Arabidopsis, AtWUS, AtWOX5, and AtWOX4, function in the SAM, RAM, and VC, respectively. Identifying the function of CrWUL will provide insights on the progenitor function and the diversification of the modern WOX genes in seed plants.ResultsTo investigate the role of CrWUL in the fern, we examined the expression and function of CrWUL and found it expresses during early root development and in vasculature but not in the SAM. Knockdown of CrWUL by RNAi produced plants with fewer roots and fewer phloem cells. When expressed in Arabidopsis cambium, CrWUL was able to complement AtWOX4 function in an atwox4 mutant, suggesting that the WOX function in VC is conserved between ferns and angiosperms. Additionally, the proposed progenitor of T3WOX genes from Selaginella kraussiana is expressed in the vasculature but not in the shoot apical meristem. In contrast to the sporophyte, the expression of CrWUL in the gametophyte exhibits a more general expression pattern and when knocked down, offered little discernable phenotypes.ConclusionsThe results presented here support the occurrence of co-option of the T3WOX/modern clade gene from the gametophyte to function in vasculature and root development in the sporophyte. The function in vasculature is likely to have existed in the progenitor of lycophyte T3WOX/modern clade genes and this function predates its SAM function found in many seed plants.

The Effect of Passive Ultrasonic Irrigation or XP-Endo Finisher on Post-Operative Pain in Patients with Necrotic Teeth with Apical Periodontitis (Randomized Controlled Clinical Trial)

Objective To evaluate the effect of passive ultrasonic irrigation or XP-Endo Finisher on post-operative pain in patients with necrotic teeth with apical periodontitis using (VAS) scale at 6, 12, 24, 48, 72 hours, and 7 day time intervals.&#x0D; Methods Seventy-eight patients diagnosed with necrotic mandibular first molar with symptomatic apical periodontitis were randomly allocated into 1 of 3 separate groups (n=26); Navitip group (control), XP-Endo Finisher group, or Ultra X group. After a single visit root canal treatment and a specific method of agitation, depending on each group, the patients were given a questionnaire on which the patient would mark the degree of pain in a scale from 0 to 10 at 6, 12, 24, 48, 72 hours and 7 days post-obturation. Data were statistically analyzed with a significance level of P ≤ 0.05.&#x0D; Results Ultrasonic agitation and XP-Endo Finisher agitation as a final irrigation protocol showed significantly lower pain values than the control group, but there was no significant difference in pain values between the experimental groups.&#x0D; Conclusion There was significantly less pain associated with ultrasonic and XP-Endo Finisher agitation compared to Navitip irrigation.

Spectral properties of a class of treelike networks generated by motifs with single root node

In this paper, we introduce a class of treelike networks generated by motifs with single root node. We study the spectral properties of treelike networks by studying the behaviors of the corresponding adjacency matrix and Laplacian matrix. First, we get the adjacency matrix and Laplacian matrix of this treelike network. Then, we analyze symmetry of eigenvalues, multiplicity of eigenvalue [Formula: see text] and prove that its largest eigenvalue is strictly monotonically increasing and convergent. Finally, we introduce a new method to prove that the largest eigenvalue of the Laplacian matrix is strictly monotonically increasing and convergent. Also, we obtain that its smallest nonzero eigenvalue is strictly monotonically decreasing and convergent.

Lumbar nerve root biopsy with fascicle dissection and functional mapping: how I do it.

Lumbosacral plexopathies with unclear etiology are a rare entity. In certain cases, if workup unrevealing and medical management is suboptimal, an open lumbar nerve root biopsy may be considered. A standard lumbar laminectomy is performed for access to the intradural contents. The dura is opened at midline in a standard fashion. Single nerve roots are selected and stimulated for an EMG response. A nerve fascicle is then dissected and stimulated before excision. Lumbar nerve root biopsy is feasible and safe. All non-invasive workup needs to be completed and negative before performing this procedure.

A Chinese tale of three regions: a century of China in thousands of films

Over the past 70 years, because of their different historical and social contexts, the film industries of China’s three regions, namely mainland China, Taiwan, and the Hong Kong Special Administrative Region (SAR), have exhibited distinct characteristics that grow out of a single cultural root. Based on data from the Internet Movie Database (IMDb), this study investigates how the image of China has spread overseas through cultural products by applying big data analysis and machine learning methods to compare the content, topics, and attitudes toward the image of China disseminated by films originating in these three regions. The results show that the three areas have sought to express their subjectivity during periods of flux and striven to connect with the world in films. The macroscopic analysis of large-scale content allows the exploration of hidden cultural phenomena and compensates for the lack of objectivity of traditional research methods, while understanding embedded historical and cultural contexts of the three regions helps to clarify the regions’ ethnic, cultural, and emotional connections. Therefore, this study has contributed to cultural sociology both in topic and methodology.

Visualising the effect of freezing on the vascular system of wheat in three dimensions by in‐block imaging of dye‐infiltrated plants

Infrared thermography has shown after roots of grasses freeze, ice spreads into the crown and then acropetally into leaves initially through vascular bundles. Leaves freeze singly with the oldest leaves freezing first and the youngest freezing later. Visualising the vascular system in its native 3‐dimensional state will help in the understanding of this freezing process. A 2 cm section of the crown that had been infiltrated with aniline blue was embedded in paraffin and sectioned with a microtome. A photograph of the surface of the tissue in the paraffin block was taken after the microtome blade removed each 20 μm section. Two hundred to 300 images were imported into Adobe After Effects and a 3D volume of the region infiltrated by aniline blue dye was constructed. The reconstruction revealed that roots fed into what is functionally a region inside the crown that could act as a reservoir from which all the leaves are able to draw water. When a single root was fed dye solution, the entire region filled with dye and the vascular bundles of every leaf took up the dye; this indicated that the vascular system of roots was not paired with individual leaves. Fluorescence microscopy suggested the edge of the reservoir might be composed of phenolic compounds. When plants were frozen, the edges of the reservoir became leaky and dye solution spread into the mesophyll outside the reservoir. The significance of this change with regard to freezing tolerance is not known at this time.Thermal cameras that allow visualisation of water freezing in plants have shown that in crops like wheat, oats and barley, ice forms first at the bottom of the plant and then moves upwards into leaves through water conducting channels. Leaves freeze one at a time with the oldest leaves freezing first and then younger ones further up the stem freeze later. To better understand why plants freeze like this, we reconstructed a 3‐dimensional view of the water conducting channels. After placing the roots of a wheat plant in a blue dye and allowing it to pull the dye upwards into leaves, we took a part of the stem just above the roots and embedded it in paraffin. We used a microtome to slice a thin layer of the paraffin containing the plant and then photographed the surface after each layer was removed. After taking about 300 images, we used Adobe After Effects software to re‐construct the plant with the water conducting system in three dimensions. The 3D reconstruction showed that roots fed into a roughly spherical area at the bottom of the stem that could act as a kind of tank or reservoir from which the leaves pull up water. When we put just one root in dye, the entire reservoir filled up and the water conducting channels in every leaf took up the dye. This indicates that the water channels in roots were not directly connected to specific leaves as we had thought. When plants were frozen, the dye leaked out of the reservoir and spread into cells outside. Research is continuing to understand the significance of this change during freezing. It is possible that information about this effect can be used to help breeders develop more winter‐hardy crop plants.

Evaluation of root and canal morphologies of permanent canines in a Saudi Arabian sub population using cone-beam computed tomography

Background/purposeFailure to identify and treat the root canal system in its entirety has been known to be one of the leading causes of unsuccessful root canal treatment (RCT). This study aims to retrospectively assess the permanent canines in a Saudi Arabian sub population for the number of roots, root canal morphologies and the presence of symmetry among them using cone-beam computed tomography (CBCT). Materials and methodsCBCT scans belonging to 945 patients were screened. A total of 1880 permanent canines, 928 pertaining to maxilla and 952 pertaining to mandible were analyzed for the number of roots, root canal morphologies and the presence of symmetry among them. Comparative evaluation between genders was done using Fisher's exact test, since majority of the groups had expected count of less than 5. A calculated P-value of less than 0.05 was considered significant. Chi square test was used for statistical analysis of the data. Intra operator variability was observed using Cohen's Kappa test. ResultsSingle root was observed in 100% and 98.7% of the maxillary and mandibular canines respectively. Two roots were identified in 1.3% of the MnC's. Type I (97.48%), Type II (0.21%), Type III (1.05%) and Type V (1.26%) Vertucci canal configurations (VC) were observed in MnC's. Statistical significant difference was observed concerning the number of roots and canal morphology according to Vertucci in the mandibular canines. No difference was observed according to Ahmed et al. classification system. Moreover, there was no gender based difference seen among them. ConclusionMore variable root and canal morphologies are observed in MnC's, although single root with Type I VC is the most common.