Comparison of Attachment Types in Maxillary Implant-assisted Obturators using Digital Image Correlation Analysis.

AIM: The purpose of the study was to evaluate the stress on the implant and to assess the denture displacement for locator and bar and clip attachment types in implant-assisted obturators. MATERIALS AND METHODS: A maxillary edentulous experimental model with a maxillectomy defect was made along with an opposing edentulous mandibular model with self-cure acrylic. Two endosseous implants were placed in the maxillary model. Corresponding obturator complete denture was fabricated for the maxillary model and a complete denture for the mandibular. The attachments were positioned on the implants in maxillary model, and their sleeve/clip was placed on intaglio surface of the dentures. The mounted articulator was placed on a loading apparatus, and force was incrementally applied to it. The strain and displacement for both the attachment types were measured and compared using Digital Image Correlation (DIC). RESULTS: Locator attachment showed the least stress and minimal displacement as compared to bar and clip attachment. CONCLUSION: The stresses around the implants and displacement of the obturator are affected by the attachment type used. It was found that bar and clip (splinted) showed the maximum stresses around the implant and maximum denture displacement. Locator attachment is the better choice over bar and clip because of its additional retentive features. CLINICAL SIGNIFICANCE: The advantage of using DIC over the conventional strain gauge analysis is that a full-field data of displacement and strain can be obtained instead of getting a mean value on the small surface where the strain gauge is positioned.

Characterization of natural genetic variation identifies multiple genes involved in salt tolerance in maize.

Progressive decline in irrigation water is forcing farmers to use brackish water which increases soil salinity and exposes the crop plants to salinity. Maize, one of the most important crops, is sensitive to salinity. Salt tolerance is a complex trait controlled by a number of physiological and biochemical processes. Scant information is available on the genetic architecture of salt tolerance in maize. We evaluated 399 inbred lines for six early vigor shoot and root traits upon exposure of 18-day seedlings to salinity (ECiw = 16 dS m-1) stress. Contrasting response of shoot and root growth to salinity indicated a meticulous reprogramming of resource partitioning by the plants to cope with the stress. The genomic analysis identified 57 single nucleotide polymorphisms (SNP) associated with early vigor traits. Candidate genes systematically associated with each SNP include both previously known and novel genes. Important candidates include a late embryogenesis protein, a divalent ion symporter, a proton extrusion protein, an RNA-binding protein, a casein kinase 1, and an AP2/EREBP transcription factor. The late embryogenesis protein is associated with both shoot and root length, indicating a coordinated change in resource allocation upon salt stress. Identification of a casein kinase 1 indicates an important role for Ser/Thr kinases in salt tolerance. Validation of eight candidates based on expression in a salt-tolerant and a salt-sensitive inbred line supported their role in salt tolerance. The candidate genes identified in this investigation provide a foundation for dissecting genetic and molecular regulation of salt tolerance in maize and related grasses.

Outcomes after long-term mechanical ventilation of cancer patients.

BACKGROUND: The probability of weaning and of long-term survival of chronically mechanically ventilated cancer patients is unknown, with incomplete information available to guide therapeutic decisions. We sought to determine the probability of weaning and overall survival of cancer patients requiring long-term mechanical ventilation in a specialized weaning unit. METHODS: A single-institution retrospective review of patients requiring mechanical ventilation outside of a critical care setting from 2008 to 2012 and from January 1 to December 31, 2018, was performed. Demographic and clinical data were recorded, including cancer specifics, comorbidities, treatments, and outcomes. Overall survival was determined using the Kaplan-Meier approach. Time to weaning was analyzed using the cumulative incidence function, with death considered a competing risk. Prognostic factors were evaluated for use in prospective evaluations of weaning protocols. RESULTS: Between 2008 and 2012, 122 patients required mechanical ventilation outside of a critical care setting with weaning as a goal of care. The cumulative incidence of weaning after discharge from the intensive care unit was 42% at 21 days, 49% at 30 days, 58% at 60 days, 61% at 90 days, and 61% at 120 days. The median survival was 0.16 years (95% CI, 0.12 to 0.33) for those not weaned and 1.05 years (95% CI, 0.60 to 1.34) for those weaned. Overall survival at 1 year and 2 years was 52 and 32% among those weaned and 16 and 9% among those not weaned. During 2018, 36 patients at our institution required mechanical ventilation outside of a critical care setting, with weaning as a goal of care. Overall, with a median follow-up of 140 days (range, 0-425 days; average, 141 days), 25% of patients requiring long-term mechanical ventilation (9 of 36) are alive. CONCLUSIONS: Cancer patients can be weaned from long-term mechanical ventilation, even after prolonged periods of support. Implementation of a resource-intensive weaning program did not improve rates of successful weaning. No clear time on mechanical ventilation could be identified beyond which weaning was unprecedented. Short-term overall survival for these patients is poor.

Molecular characterization and expression analysis of the Na+/H+ exchanger gene family in Medicago truncatula.

One important mechanism plants use to cope with salinity is keeping the cytosolic Na+ concentration low by sequestering Na+ in vacuoles, a process facilitated by Na+/H+ exchangers (NHX). There are eight NHX genes (NHX1 through NHX8) identified and characterized in Arabidopsis thaliana. Bioinformatics analyses of the known Arabidopsis genes enabled us to identify six Medicago truncatula NHX genes (MtNHX1, MtNHX2, MtNHX3, MtNHX4, MtNHX6, and MtNHX7). Twelve transmembrane domains and an amiloride binding site were conserved in five out of six MtNHX proteins. Phylogenetic analysis involving A. thaliana, Glycine max, Phaseolus vulgaris, and M. truncatula revealed that each individual MtNHX class (class I: MtNHX1 through 4; class II: MtNHX6; class III: MtNHX7) falls under a separate clade. In a salinity-stress experiment, M. truncatula exhibited ~ 20% reduction in biomass. In the salinity treatment, sodium contents increased by 178 and 75% in leaves and roots, respectively, and Cl- contents increased by 152 and 162%, respectively. Na+ exclusion may be responsible for the relatively smaller increase in Na+ concentration in roots under salt stress as compared to Cl-. Decline in tissue K+ concentration under salinity was not surprising as some antiporters play an important role in transporting both Na+ and K + . MtNHX1, MtNHX6, and MtNHX7 display high expression in roots and leaves. MtNHX3, MtNHX6, and MtNHX7 were induced in roots under salinity stress. Expression analysis results indicate that sequestering Na+ into vacuoles may not be the principal component trait of the salt tolerance mechanism in M. truncatula and other component traits may be pivotal.

Prosthetic rehabilitation of surgically treated orbital defects - evisceration, enucleation, and exenteration: A case series.

The rehabilitation of a patient who has suffered the psychological trauma due to loss of an eye requires a prosthesis that will provide the optimum cosmetic and functional result. The mode of rehabilitation varies based on the type of defect and surgical approach being adopted. A case series of prosthetic rehabilitation of three types of orbital defects - evisceration, enucleation and exenteration have been reported in this article. The clinical relevance of surgical approaches highlights the preservation of remaining anatomic structures creating a negative space or concavity to aid in future prosthetic rehabilitation. A multidisciplinary management and team approach is essential in providing esthetics and to regain the confidence. Follow-up care for the patient is mandatory.

Mandibular implant-supported overdenture: an in vitro comparison of ball, bar, and magnetic attachments.

In an implant-supported overdenture, the optimal stress distribution on the implants and least denture displacement is desirable. This study compares the load transfer characteristics to the implant and the movement of overdenture among 3 different types of attachments (ball-ring, bar-clip, and magnetic). Stress on the implant surface was measured using the strain-gauge technique and denture displacement by dial gauge. The ball/O-ring produces the optimal stress on the implant body and promotes denture stability.

Bite Force Evaluation in Implant-Assisted Prosthetic Rehabilitation of Reconstructed Jaws Utilizing Vascularized Free Fibula Flap: A Retro-Prospective Cohort Study.

Introduction: Maxillary and mandibular defects due to tumor ablation pose considerable challenges to the reconstructive surgeon and in prosthetic management. Dental implants placed in vascularized fibula free flaps are considered to be a dependable technique for prosthetic rehabilitation in head and neck cancer patients. Although, there is evidence of survival of dental implants in the reconstructed jaw bones, there is lack of information regarding the masticatory performance and prosthetic success. The maximum bite force achieved through the prosthetic appliance is a measure of the therapeutic outcome. The purpose of this study was to determine the maximum bite force achieved through implant-assisted prosthetic rehabilitation in reconstructed jaw bones utilizing vascularized free fibula flap. Methods: The study included a total of 65 implants, from 16 patients who underwent surgical resection of jaw bones due to benign tumors followed by rehabilitation with implant-assisted fixed or removable prosthesis. The maximum bite force was determined with a transducer. Occlusal interferences were analyzed with mounted casts. The parameters were reviewed every 3 months have T 0 marked the baseline assessment, and T 3, T 6, T 9, T 12, and T 15 were subsequent review periods. Results: The mean occlusal force was increased in most of the patients through 15 months (P < 0.01). The maximum bite force measured in the reconstructed mandible and maxilla were 225.63 N and 176.51 N, respectively. Occlusal interferences were absent in 68.8% of the study population. Conclusion: The bite force measured in reconstructed maxilla and mandible is comparable to the masticatory force measured with conventional implant supported prosthesis in native mandible and maxilla.

NANOTEX BONE Graft along with Fibula Flap in the Reconstruction of Segmental Mandibular Defect: Protocol for Pilot Clinical Trial.

Introduction and objectives: Mandible reconstruction with vascularized fibula flap is the standard treatment for segmental mandibulectomy in patients with tumor or trauma. But the height of the fibula graft is insufficient for dental implant placement and prosthetic rehabilitation to replace the missing teeth, which in turn will compromise the functional efficiency and aesthetics of the patient. Although the bone height can be augmented through onlay grafting with iliac crest, it is associated with limitations like donor site morbidity and fast resorbability. This suggests the need for a synthetic biomaterial for vertical bone augmentation in implant dentistry.We have developed a biomimetic, porous, mechanically stable, and biodegradable nanocomposite named "NANOTEX BONE Graft" and its bone regeneration potential was evaluated in pre-clinical animal models. In this clinical trial, the safety as well as the efficacy of NANOTEX to augment new bone over fibula and further its ability to integrate with dental implants will be studied. The study has received the approval of the Ethics Committee of Amrita Institute of Medical Sciences and Central Drugs Standard Control Organization (CDSCO), India. Methods: We have designed a prospective, single-center, non-randomized pilot clinical study. Patients with benign tumor or trauma indicated for mandibular reconstruction followed by implant rehabilitation will be included in the study. Eligible patients will be enrolled after obtaining informed consent. The study will be initiated and followed up as per defined timelines. Highlights: Resection of benign mandibular tumours necessitates surgical removal of jaw bone and adjacent affected areas.The segmental mandibulectomy leaves the patient with functional impairments and aesthetic defects which in turn affect the quality of life.The standard treatment of reconstruction with vascularized fibula flap has challenge in achieving sufficient vertical bone height for implant placement and prosthetic rehabilitation.Alternate surgical techniques cause donor site morbidity and surgical complications.There is need for a synthetic biomaterial to be grafted over fibula for vertical bone augmentation.NANOTEX BONE Graft, a nanofibrous composite scaffold that mimics native bone, promote cell infiltration, neo-angiogenesis and new bone formation.Preclinical studies of NANOTEX in animal models showed bone tissue regeneration, better biodegradation in critical sized defects and efficient integration with dental implants.This clinical study propose to evaluate the safety and efficacy of NANOTEX bone graft augmented over fibula in bone regeneration and Titanium dental implant integration.

Prosthetic Rehabilitation Options in Post-Ablative Maxillomandibular Microvascular Reconstructions.

Objective: Surgery remains the mainstay for managing most neoplasms arising in the head and neck area. Removable or fixed prostheses are commonly used for prosthetic rehabilitation of head and neck defects following surgical resection. Some major challenges in prosthetic rehabilitation after maxillomandibular microvascular reconstruction include excessive prosthetic space, soft tissue bulk, and occlusal disharmony in the remaining dentition. This review focuses on the challenges we have experienced in the real clinical scenario while rehabilitating reconstructed maxillomandibular defects and the effective prosthetic treatment options that could be considered in each situation. Discussion: Digital revolution has changed all arenas of life, and it has created a significant impact on cancer treatment planning and the delivery of quality treatment to the needy. Creating adequate retention while ensuring stability and support for the prosthesis can be challenging with temporary acrylic and cast partial removable dentures. Endosseous dental implants are considered a stable, reliable, and esthetic option for reconstruction with advantages such as increased chewing efficiency, preservation of the remaining bone height and width, and improved quality of life. The FP3 to RP5 (Misch's classification) are some commonly followed prosthetic rehabilitation options after microvascular reconstruction. The prosthetic design should permit the usage of interdental aids that ensure the longevity of prostheses. Conclusion: Occlusion-driven/prosthetic-driven implant-assisted prostheses are considered a reliable option that ensures stable and functional oral rehabilitation among patients with free fibula flap reconstruction. Multidisciplinary teamwork is mandatory for an optimal outcome that improves patients' quality of life.

Patient Specific Alloplastic Implant Reconstruction of Mandibular Defects-Safe Practice Recommendations and Guidelines.

Mandibular continuity defects are commonly seen after tumor resection, osteomyelitis or maxillofacial trauma. Three-dimensional reconstruction of these mandibular segmental defects is critical for proper mandibular functioning and esthetics. Various methods used to reconstruct such defects include bridging reconstruction plates, modular endoprosthesis, non-vascularized and vascularized bone grafting with stock reconstruction plate or patient specific implants (PSI) and tissue engineering bone transfer. But in the recent years, literature documents use of PSI only alloplastic reconstruction as an alternate to microvascular bone flap reconstruction. Representative cases enumerate current practice of 'patient specific implant only' mandibular reconstruction and its pitfalls. This article discusses current status of literature on PSI's, choice of indications for 'PSI only' mandibular reconstruction and also proposes guidelines for safe practice of patient specific implant reconstruction of mandible.

Controlling and Stabilising Mandible During Reconstruction: Significance and Techniques.

Objective: Stable and accurate positioning of condyle in the glenoid fossa is necessary for maintaining occlusion, facial symmetry and normal function of the temporomandibular joint following segmental resection of mandible. In non-reconstructed mandibular segments or those with fractured reconstruction plates the bony defect gets altered due to contraction or inadvertent muscular pull. This paper describes various techniques used to control dentate and edentate segments of the mandible during reconstruction following an ablative procedure. Discussion: Secondary mandibular reconstruction has always been a tedious task for the surgeons. Several techniques have been described in literature ranging the use of external fixators, gunning splints and dentures for stabilising mandibular segments. Use of a pre-bent and adapted reconstruction plate is a common practice but may not be feasible in malignancies, benign tumours causing expansion and secondary reconstruction. The current advances in virtual surgical planning allows mandibular reconstruction to be performed in a simpler yet predictable manner. Conclusion: The paper describes techniques ranging from twin K-wire placement to occlusal wafers, 3D printed splints and patient specific implants to enable accurate positioning of the segments and achieve pre-operative form. Advances in virtual surgical planning will continue to allow this field to evolve and to improve the quality of life of the patients.

Relevance of Recurring Esthetic Dental (RED) proportion and golden proportion among patients attending a tertiary care center at Kochi, Kerala.

Background: Smile plays an essential part in facial esthetics. There have been some mathematical and geometric theories regarding smile designing in literature. The purpose of the study was to assess RED proportion and golden proportion among patients attending a tertiary care centre at Kochi, Kerala. Methods: Standardised frontal images of 106 subjects, 50 male and 56 females, were captured in the age bracket of 18-25 years. Pictures of the patients were obtained using a DSLR camera (CANON EOS-60D) and then digitally analysed. Measurements of each maxillary anterior tooth was recorded and then the theories of RED and golden proportion were employed and the figures recorded were statistically analysed. Results: The RED proportion was observed to be inconsistent, while progressing distally, Golden proportion was observed to be in 6-29% of the existing subject population. Conclusion: Within the limited sample size of the study, RED (Recurring Esthetic Dental) proportion and golden proportion failed to exist in Keralites.

Nanocomposite fibrous scaffold mediated mandible reconstruction and dental rehabilitation: An experimental study in pig model.

Mandible reconstruction and dental rehabilitation after trauma or tumor resection represent a serious challenge for maxillofacial surgeons. This study aimed to investigate the bone formation potential of nanocomposite fibrous scaffold (silica-nanohydroxyapatite-gelatin reinforced with poly L-lactic acid yarns - CSF) for delayed Titanium (Ti) implantation, which was compared to autograft (AG) taken from the iliac crest. The grafts were placed in critical-sized mandibular defects in an adult pig model for 6 months followed by dental implant placement for another 3 months. There was complete union and vascularised lamellar bone formation within 6 months. Moreover, the biological processes associated with angiogenesis, bone maturation and remodelling were seen in CSF, which was comparable to AG. Later, when Ti dental implant was placed on newly formed bone, CSF group demonstrated better osseointegration. In short, nanocomposite fibrous scaffold promoted quality bone formation in mandible defect that leads to successful osseointegration, suggesting as a potential candidate for implant-based rehabilitation in clinics in future.

Analysis of factors determining thermal changes at osteotomy site in dental implant placement - An in-vitro study.

BACKGROUND: Heat generation during osteotomy site preparation is a crucial factor that determines the success of dental implant placement. Among the factors that affect the heat generation, drilling speed, hand pressure and coolant temperature are independent variables. However, a relation between these three parameters and their optimal values required for the maximum outcome has not been studied so far. This study aims at finding out a relation between these factors in order to derive the optimum balance required, using an in vitro study. MATERIAL AND METHODS: This in vitro experiment was performed on bovine femur. A total of 72 drillings were undertaken with the aid of a physiodispenser mounted on the test apparatus. Drill diameters of 2 mm and 2.8 mm, rotated at 1500, 2000 and 2500 rpm were included for the analysis. Hand pressures included for the comparison were 1.2 kgf and 2.4 kgf. Normal saline at room temperature, and that chilled to 00C were used for external irrigation. The temperature generated during drilling was recorded by infrared thermography using a Forward-Looking Infrared (FLIR) camera. RESULTS: The highest temperature during osteotomy was observed at 2000 rpm rotational speed, 1.2 kgf operator hand pressure and saline irrigant solution at room temperature. In contrast, the lowest temperature generated was using 2500 rpm rotational speed, 2.4 kgf operator hand pressure and chilled irrigant solution. CONCLUSIONS: The results indicate that none of the three experimented parameters generated heat above the critical temperature for bone necrosis (47°C). Thus, a high drilling speed with high hand pressure and continuous irrigation with copious amounts of cooled saline may be the ideal combination for implant osteotomy site preparation. Key words:Heat generation, dental implant drills, drilling speed, drilling pressure, irrigation, infrared thermography, thermal necrosis, osteotomy preparation.

Transcriptional profiling of two contrasting genotypes uncovers molecular mechanisms underlying salt tolerance in alfalfa.

Alfalfa is an important forage crop that is moderately tolerant to salinity; however, little is known about its salt-tolerance mechanisms. We studied root and leaf transcriptomes of a salt-tolerant (G03) and a salt-sensitive (G09) genotype, irrigated with waters of low and high salinities. RNA sequencing led to 1.73 billion high-quality reads that were assembled into 418,480 unigenes; 35% of which were assigned to 57 Gene Ontology annotations. The unigenes were assigned to pathway databases for understanding high-level functions. The comparison of two genotypes suggested that the low salt tolerance index for transpiration rate and stomatal conductance of G03 compared to G09 may be due to its reduced salt uptake under salinity. The differences in shoot biomass between the salt-tolerant and salt-sensitive lines were explained by their differential expressions of genes regulating shoot number. Differentially expressed genes involved in hormone-, calcium-, and redox-signaling, showed treatment- and genotype-specific differences and led to the identification of various candidate genes involved in salinity stress, which can be investigated further to improve salinity tolerance in alfalfa. Validation of RNA-seq results using qRT-PCR displayed a high level of consistency between the two experiments. This study provides valuable insight into the molecular mechanisms regulating salt tolerance in alfalfa.

Supplementation of deprenyl attenuates age associated alterations in rat cerebellum.

Aging, a multifactorial process of enormous complexity is characterised by physio-chemical and biological aspects of cellular functions. It is closely associated with changes in metabolism of various biological molecules in the system. In the present study, we have investigated the effect of deprenyl on cerebellum during ageing process in male Wistar rats with respect to the changes in levels of protein, glycoproteins and amino acids in experimental rats of three age groups (6, 12 and 18 months old). Intraperitoneal administration of liquid deprenyl (2 mg/kg body weight/day for a period of 15 days i.p., significantly P < 0.05) attenuated age-associated alterations in the levels of amino acids (taurine, aspartate, glutamate, arginine, hydroxy proline and homocysteine), protein content and glycoprotein components (hexose and hexosamine) in the rat cerebellum. The results of the present investigation indicate that the protective effect of deprenyl is probably related to its ability to strengthen the neuronal membrane by its membrane stabilizing action or to a counteraction of free radicals by its antioxidant property.

Linking diverse salinity responses of 14 almond rootstocks with physiological, biochemical, and genetic determinants.

Fourteen commercial almond rootstocks were tested under five types of irrigation waters to understand the genetic, physiological, and biochemical bases of salt-tolerance mechanisms. Treatments included control (T1) and four saline water treatments dominant in sodium-sulfate (T2), sodium-chloride (T3), sodium-chloride/sulfate (T4), and calcium/magnesium-chloride/sulfate (T5). T3 caused the highest reduction in survival rate and trunk diameter, followed by T4 and T2, indicating that Na and, to a lesser extent, Cl were the most toxic ions to almond rootstocks. Peach hybrid (Empyrean 1) and peach-almond hybrids (Cornerstone, Bright's Hybrid 5, and BB 106) were the most tolerant to salinity. Rootstock's performance under salinity correlated highly with its leaf Na and Cl concentrations, indicating that Na+ and Cl- exclusion is crucial for salinity tolerance in Prunus. Photosynthetic rate correlated with trunk diameter and proline leaf ratio (T3/T1) significantly correlated with the exclusion of Na+ and Cl-, which directly affected the survival rate. Expression analyses of 23 genes involved in salinity stress revealed that the expression differences among genotypes were closely associated with their performance under salinity. Our genetic, molecular, and biochemical analyses allowed us to characterize rootstocks based on component traits of the salt-tolerance mechanisms, which may facilitate the development of highly salt-tolerant rootstocks.

Effect of chemical disinfectants and accelerated aging on maxillofacial silicone elastomers: An In vitro Study.

CONTEXT: Maxillofacial prostheses need frequent refabrication due to degradation of color and deterioration of physical properties of the elastomer. AIMS: This study attempted to evaluate the change in color stability, Shore A hardness, and surface roughness of two maxillofacial silicones, A-2186 and Cosmesil M511, when submitted to chemical disinfection and accelerated aging. SETTINGS AND DESIGN: This was a comparative in vitro study. SUBJECTS AND METHODS: The materials included two silicone elastomers - A-2186 and Cosmesil M511 (Factor II Incorporated) - functional intrinsic red pigment and three disinfectants - Fittydent tablet, chlorhexidine gluconate 4%, and neutral soap. The specimens in each group of elastomer were evaluated initially for color, hardness, and surface roughness, which were further divided into subgroups and subjected to disinfection and accelerated aging. The evaluation of color was performed with the help of an ultraviolet reflectance spectrophotometer. Shore A hardness was evaluated using a durometer and surface roughness, with a digital roughness tester followed by scanning electron microscopy analysis. STATISTICAL ANALYSIS USED:: Analysis of variance and Tukey's multiple comparison test were used for statistical analysis. RESULTS: Accelerated aging caused a significant decrease in color, increase in Shore A hardness, and variation in surface roughness in both silicone elastomer groups. Chemical disinfection presented significant changes in color and surface roughness whereas no significant effect on Shore hardness, irrespective of the disinfectant used. CONCLUSIONS: The maxillofacial silicone elastomers presented deterioration in color, hardening, and significant variations in surface roughness when subjected to chemical disinfection and accelerated aging, which provides a valid baseline for future research.

Nanofibrous yarn reinforced HA-gelatin composite scaffolds promote bone formation in critical sized alveolar defects in rabbit model.

Alveolar ridge resorption and crestal bone loss necessitate the use of bone graft substitutes for dental rehabilitation. The aim of this study was to compare the bone regenerative property of nanofibre incorporated two composite matrices (nanofibrous sheet layered matrix (CS-S) and nanofibrous yarn reinforced matrix (CS-Y)) in critical sized mandibular defect in a rabbit model (under load bearing scenario). Histological evaluation revealed continuous bone formation in the defect implanted with fibre reinforced scaffolds than those without fibres as well as commercial nanoHA-collagen graft. Interestingly, the mineralisation and the mineral density were significantly higher with nanoyarn reinforced scaffolds. Moreover, the compressive strength of new bone formed from CS-Y scaffolds was almost similar to that of native rabbit mandible. It can be concluded that the mechanical strength provided by three-dimensionally reinforced nanoyarns in the matrix could promote bone formation in load bearing mandibular region, and these can be proposed as a scaffold of choice for alveolar bone augmentation and dental rehabilitation.

Divergence in pollen performance between Clarkia sister species with contrasting mating systems supports predictions of sexual selection.

Animal taxa that differ in the intensity of sperm competition often differ in sperm production or swimming speed, arguably due to sexual selection on postcopulatory male traits affecting siring success. In plants, closely related self- and cross-pollinated taxa similarly differ in the opportunity for sexual selection among male gametophytes after pollination, so traits such as the proportion of pollen on the stigma that rapidly enters the style and mean pollen tube growth rate (PTGR) are predicted to diverge between them. To date, no studies have tested this prediction in multiple plant populations under uniform conditions. We tested for differences in pollen performance in greenhouse-raised populations of two Clarkia sister species: the predominantly outcrossing C. unguiculata and the facultatively self-pollinating C. exilis. Within populations of each taxon, groups of individuals were reciprocally pollinated (n = 1153 pollinations) and their styles examined four hours later. We tested for the effects of species, population, pollen type (self vs. outcross), the number of competing pollen grains, and temperature on pollen performance. Clarkia unguiculata exhibited higher mean PTGR than C. exilis; pollen type had no effect on performance in either taxon. The difference between these species in PTGR is consistent with predictions of sexual selection theory.