Positive correlational shift between crevicular antimicrobial peptide LL-37, pain and periodontal status following non-surgical periodontal therapy. A pilot study.

BACKGROUND: Periodontitis has a high prevalence and uncertain recurrence. Unlike the pro-inflammatory cytokine profile, little is known about the anti-inflammatory cytokine and antimicrobial peptide overview following treatment. The present study aimed to evaluate if any of the antimicrobial peptide LL-37, interleukin (IL) 4, 10 and 6 together with the volume of gingival crevicular fluid (GCF) and total protein concentration in GCF could be used as correlative biomarkers for the severity in periodontitis as well as prognostic factors in the management of the disease. METHODS: Forty-five participants were recruited and allocated to the healthy (15), Stage I-II (15) or Stage III-IV periodontitis (15) group. Along with periodontal examination, GCF samples were obtained at baseline and 4-6 weeks following scaling and root planing (SRP) for the periodontitis groups. GCF samples were analyzed by ELISA kits to quantify LL-37 and IL-4, -6 and - 10. One-way ANOVA followed by Dunnett's test was used to determine differences among the three groups at baseline. Two-way ANOVA followed by Sidak's post-hoc test was used to compare between pre- and post-SRP in the two periodontitis groups. RESULTS: The amount of GCF volume was significantly correlated to the severity of periodontitis and decreased following SRP, particularly in the Stage III-IV group (p < 0.01). The levels of LL-37, IL-6, and pain and periodontal clinical parameters were significantly correlated to the severity of periodontitis. IL-4 and IL-10 in the periodontitis groups were significantly lower than the healthy group (p < 0.0001) and barely improved following SRP up to the level of the healthy group. CONCLUSIONS: With the limitations of this study, crevicular LL-37 may be a candidate for a biomarker of periodontitis and the associated pain upon probing. TRIAL REGISTRATION: The study was registered in clinical trials.gov, with number NCT04404335, dated 27/05/2020.

Supramolecular Nanoscaffolds within Cytomimetic Protocells as Signal Localization Hubs.

The programmed construction of functional synthetic cells requires spatial control over arrays of biomolecules within the cytomimetic environment. The mimicry of the natural hierarchical assembly of biomolecules remains challenging due to the lack of an appropriate molecular toolbox. Herein, we report the implementation of DNA-decorated supramolecular assemblies as dynamic and responsive nanoscaffolds for the localization of arrays of DNA signal cargo within hierarchically assembled complex coacervate protocells. Protocells stabilized with a semipermeable membrane allow trafficking of single-stranded DNA between neighboring protocells. DNA duplex operations demonstrate the responsiveness of the nanoscaffolds to different input DNA strands via the reversible release of DNA cargo. Moreover, a second population of coacervate protocells with nanoscaffolds featuring a higher affinity for the DNA cargo enabled chemically programmed communication between both protocell populations. This combination of supramolecular structure and function paves the way for the next generation of protocells imbued with programmable, lifelike behaviors.

Design of Bio-Conjugated Hydrogels for Regenerative Medicine Applications: From Polymer Scaffold to Biomolecule Choice.

Bio-conjugated hydrogels merge the functionality of a synthetic network with the activity of a biomolecule, becoming thus an interesting class of materials for a variety of biomedical applications. This combination allows the fine tuning of their functionality and activity, whilst retaining biocompatibility, responsivity and displaying tunable chemical and mechanical properties. A complex scenario of molecular factors and conditions have to be taken into account to ensure the correct functionality of the bio-hydrogel as a scaffold or a delivery system, including the polymer backbone and biomolecule choice, polymerization conditions, architecture and biocompatibility. In this review, we present these key factors and conditions that have to match together to ensure the correct functionality of the bio-conjugated hydrogel. We then present recent examples of bio-conjugated hydrogel systems paving the way for regenerative medicine applications.

Allopolyploid origin and genome differentiation of the parasitic species Cuscuta veatchii (Convolvulaceae) revealed by genomic in situ hybridization.

Interspecific hybridization and genome duplication to form allopolyploids are major evolutionary events in angiosperms. In the parasitic genus Cuscuta (Convolvulaceae), molecular data suggested the existence of species of hybrid origin. One of them, C. veatchii, has been proposed as a hybrid between C. denticulata and C. nevadensis, both included in sect. Denticulatae. To test this hypothesis, a cytogenetic analysis was performed with CMA/DAPI staining and fluorescent in situ hybridization using 5S and 35S rDNA and genomic probes. Chromosomes of C. denticulata were small with a well-defined centromeric region, whereas C. nevadensis had larger, densely stained chromosomes, and less CMA+ heterochromatic bands. Cuscuta veatchii had 2n = 60 chromosomes, about 30 of them similar to those of C. denticulata and the remaining to C. nevadensis. GISH analysis confirmed the presence of both subgenomes in the allotetraploid C. veatchii. However, the number of rDNA sites and the haploid karyotype length in C. veatchii were not additive. The diploid parentals had already diverged in their chromosomes structure, whereas the reduction in the number of rDNA sites more probably occurred after hybridization. As phylogenetic data suggested a recent divergence of the progenitors, these species should have a high rate of karyotype evolution.

Cladogenesis and reticulation in Cuscuta sect. Denticulatae (Convolvulaceae).

As traditionally circumscribed, Cuscuta sect. Denticulatae is a group of three parasitic plant species native to the deserts of Western USA (Cuscuta denticulata, Cuscuta nevadensis) and the central region of Baja California, Mexico (Cuscuta veatchii). Molecular phylogenetic studies confirmed the monophyly of this group and suggested that the disjunct C. veatchii is a hybrid between the other two species. However, the limited sampling left the possibility of alternative biological and methodological explanations. We expanded our sampling to multiple individuals of all the species collected from across their entire geographical ranges. Sequence data from the nuclear and plastid regions were used to reconstruct the phylogeny and find out if the topological conflict was maintained. We obtained karyotype information from multiple individuals, investigated the morphological variation of the group thorough morphometric analyses, and compiled data on ecology, host range, and geographical distribution. Our results confirmed that C. veatchii is an allotetraploid. Furthermore, we found previously unknown autotetraploid population of C. denticulata, and we describe a new hybrid species, Cuscuta psorothamnensis. We suggest that this newly discovered natural hybrid is resulting from an independent (and probably more recent) hybridization event between the same diploid parental species as those of C. veatchii. All the polyploids showed host shift associated with hybridization and/or polyploidy and are found growing on hosts that are rarely or never frequented by their diploid progenitors. The great potential of this group as a model to study host shift in parasitic plants associated with recurrent allopolyploidy is discussed.

A hemispherical contact model for simplifying 3D occlusal surfaces.

STATEMENT OF PROBLEM: Currently, dental articulators can recreate mandibular movements and occlusal contacts. However, whether virtual articulators can also provide information about occluding dental surfaces, functional movements, and the mandibular condyles is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the occluding surfaces on dental casts obtained from a patient and approximate them to a hemispherical contact model. Both models were tested by digitizing the Dentatus ARL dental articulator. MATERIAL AND METHODS: A combination of photogrammetry and structure from motion methods were used to scan a Dentatus ARL articulator and representative dental casts. Using computer-aided engineering and finite element analysis, contact points and action vectors to the forces on occluding surfaces and condyles were obtained for cast and hemispherical models. This experiment was performed using centric occlusion and 3 different condylar inclinations. The Kruskal-Wallis 1-way analysis of variance on ranks test was used to allow all pairwise comparisons between condylar inclination and mechanical action vector values in each location (α=.05). RESULTS: Action vectors from the cast model and each location of the hemispherical model were calculated to show the mechanical consequences and the similarity among models. Overall, no significant differences were observed for action vectors (A20 versus A40 versus A60) at each location (dental cast/hemisphere, right condylar, and left condylar) in the analysis of dental casts and the hemisphere model (.382≤P≤.999). CONCLUSIONS: This study provided graphical information that may assist the dental professional in determining which occlusal contacts should be modified to attain condylar and balanced centric occlusion.

Principles of practice parameters for the treatment of sleep disordered breathing in the elderly and frail elderly: the consensus of the International Geriatric Sleep Medicine Task Force.

Sleep disordered breathing (SDB) is a leading cause of morbidity worldwide. Its prevalence increases with age. Due to the demographic changes in industrial societies, pulmonologists and sleep physicians are confronted with a rapidly growing number of elderly SDB patients. For many physicians, it remains unclear how current guidelines for SDB management apply to elderly and frail elderly patients. The goal of this consensus statement is to provide guidance based on published evidence for SDB treatment in this specific patient group.Clinicians and researchers with expertise in geriatric sleep medicine representing several countries were invited to participate in a task force. A literature search of PubMed from the past 12 years and a systematic review of evidence of studies deemed relevant was performed.Recommendations for treatment management of elderly and frail elderly SDB patients based on published evidence were formulated via discussion and consensus.In the last 12 years, there have been surprisingly few studies examining treatment of SDB in older adults and even fewer in frail older adults. Studies that have been conducted on the management of SDB in the older patient population were rarely stratified for age. Studies in SDB treatment that did include age stratification mainly focused on middle-aged and younger patient groups. Based on the evidence that is available, this consensus statement highlights the treatment forms that can be recommended for elderly SDB patients and encourages treatment of SDB in this large patient group.

STARTVerso1: A randomized trial of faldaprevir plus pegylated interferon/ribavirin for chronic HCV genotype-1 infection.

BACKGROUND & AIMS: The efficacy and tolerability of faldaprevir, a potent hepatitis C virus (HCV) NS3/4A protease inhibitor, plus peginterferon (PegIFN) and ribavirin (RBV) was assessed in a double-blind, placebo-controlled phase 3 study of treatment-naïve patients with HCV genotype-1 infection. METHODS: Patients were randomly assigned (1:2:2) to PegIFN/RBV plus: placebo (arm 1, n = 132) for 24 weeks; faldaprevir (120 mg, once daily) for 12 or 24 weeks (arm 2, n = 259); or faldaprevir (240 mg, once daily) for 12 weeks (arm 3, n = 261). In arms 2 and 3, patients with early treatment success (HCV-RNA <25 IU/ml at week 4 and undetectable at week 8) stopped all treatment at week 24. Other patients received PegIFN/RBV until week 48 unless they met futility criteria. The primary endpoint was sustained virologic response 12 weeks post-treatment (SVR12). RESULTS: SVR12 was achieved by 52%, 79%, and 80% of patients in arms 1, 2, and 3, respectively (estimated difference for arms 2 and 3 vs. arm 1: 27%, 95% confidence interval 17%-36%; and 29%, 95% confidence interval, 19%-38%, respectively; p < 0.0001 for both). Early treatment success was achieved by 87% (arm 2) and 89% (arm 3) of patients, of whom 86% and 89% achieved SVR12. Adverse event rates were similar among groups; few adverse events led to discontinuation of all regimen components. CONCLUSIONS: Faldaprevir plus PegIFN/RBV significantly increased SVR12, compared with PegIFN/RBV, in treatment-naïve patients with HCV genotype-1 infection. No differences were seen in responses of patients given faldaprevir once daily at 120 or 240 mg.

Subnanometer local temperature probing and remotely controlled drug release based on azo-functionalized iron oxide nanoparticles.

Local heating can be produced by iron oxide nanoparticles (IONPs) when exposed to an alternating magnetic field (AMF). To measure the temperature profile at the nanoparticle surface with a subnanometer resolution, here we present a molecular temperature probe based on the thermal decomposition of a thermo-sensitive molecule, namely, azobis[N-(2-carboxyethyl)-2-methylpropionamidine]. Fluoresceineamine (FA) was bound to the azo molecule at the IONP surface functionalized with poly(ethylene glycol) (PEG) spacers of different molecular weights. Significant local heating, with a temperature increase up to 45 °C, was found at distances below 0.5 nm from the surface of the nanoparticle, which decays exponentially with increasing distance. Furthermore, the temperature increase was found to scale linearly with the applied field at all distances. We implemented these findings in an AMF-triggered drug release system in which doxorubicin was covalently linked at different distances from the IONP surface bearing the same thermo-labile azo molecule. We demonstrated the AMF triggered distance-dependent release of the drug in a cytotoxicity assay on KB cancer cells.

Versatility of nasolabial flaps in oral cavity reconstructions.

OBJECTIVES: Describe the techniques involved and the results obtained witn nasolabial flaps in small and medium-sized defects of the oral cavity. The procedure is an easy resconstructive option with a high success rate and with very good aesthetic and functional outcomes. STUDY DESIGN: A retrospective analysis of 16 nasolabial flap reconstructions in 15 oncological patients with oral cavity defects undergoing single-stage surgical interventions. We evaluate the tumor type, its location, size, the resective and reconstructive techniques involved, as well as any complications. RESULTS: Out of 15 patients, 9 were male and 6 female, with ages ranging from 60-85 years. The primary tumor was located in the mandibular or maxillary gingiva in 7 patients, the lateral margin of the tongue in 5, the floor of the mouth in 3 and the mandibular symphysis in a single patient. The tumors were of a small to medium size. All patients underwent intraoral resections. In most cases, a cervical dissection was performed. All flaps were completed as single-stage surgical interventions, with 14 unilateral and 2 bilateral procedures. Five patients had received radiotherapy treatment for previous tumors. During the follow up period, which ranged from 4 months to 8 years, only one patient required their flap to be thinned, there were two incidents of surgical wound dehiscence, two hematomas and one orocutaneous fistula, none of which affected the survival of the flap. CONCLUSIONS: The nasolabial flap proves highly versatile in oral cavity reconstructions, coupled with a minimal morbidity of the donor region and good aesthetic and functional results. Its high vascularity allows for cervical dissections to be carried out or even for radiotherapy to be administered prior to it. It is straightforward, safe, and carrying it out as a single-stage intervention makes it the ideal surgical option for small to medium intraoral defects in edentulous patients with other comorbidities.

Predictable dental rehabilitation in maxillomandibular reconstruction with free flaps. The role of implant guided surgery.

The reconstruction of maxillomandibular defects secondary to oral cancer surgery, represent a great challenge for Maxillofacial surgeons. During the last decades the reconstructive surgery has experimented a big advance due to the development of the microsurgical techniques. At present, we are able to reconstruct complex defects using free flaps that provide both soft and bone tissue. Fibula, iliac crest and scapula free flaps have been the three classic options for the maxillomandibular reconstruction owing to the amount of bone that this flaps provide, allowing the posterior dental rehabilitation with implants. Today, our objective it is not only the aesthetic reconstruction, but also the functional reconstruction of the patients enhancing their life quality. Guided implant surgery in free flap reconstructed patients has become an essential tool, helping to define the exact position of the dental implant in the flap. In this way it is possible to look for the areas with better bone conditions, avoiding the osteosynthesis material used to fixate the flap with the native bone and deciding the best biomechanical option, in terms of number and situation of the implants, for the future dental prostheses. In summary, using the guided implant surgery, it is possible to design an exact and predictable dental implant rehabilitation in patients with oral cancer who are reconstructed with free microvascular flap, resulting in an optimal aesthetic and functional result.

Animal models in the study and treatment of orofacial pain.

BACKGROUND: Pain is one of the first causes of medical consultation in the world and by extension of dental consultation too. Orofacial pain comprehends the oral and facial regions including teeth, oral mucosa, gingiva, tongue and lips, but also the muscles of the jaw and neck, the temporomandibular joint, face, head and neck. Despite its highly estimated prevalence, it appears controversial and hard to quantify given the lack of common criteria to select the population under study and the difficulties to classify the different types of pain. Although for many patients the problem eventually fades after tissue healing, certain sub-chronic and chronic pain conditions remain notoriously undertreated. In this respect, animal models can be of great help. MATERIAL AND METHODS: A systematic search was conducted in PubMed-Medline with appropriate keywords: orofacial pain, prevalence and dentist. Seven groups were generated and a second search based on each of these groups and on animal models was made. Search was restricted to English and Spanish, but no time restriction was applied. RESULTS: There are as yet few experimental models of orofacial pain: there hardly exists no other than trigeminal nerve injury for neuropathic pain, a bunch of oral squamous cell carcinoma models (mainly referred to the tongue) for cancer pain and none for the painful swelling of salivary glands. Similarly occurs for the burning mouth syndrome. A few more exist for inflammatory odontalgiae, aphthae, joint, myofascial and muscle inflammatory pains, although scarcely diverse as regards the nature of the noxious stimulus. CONCLUSIONS: Given the relevance of envisaging the mechanistic of the various types of orofacial pain, new experimental models are needed on the basis of the dentist's perspective for their correct management. Key words:Orofacial pain, neuralgia, odontalgia, oral cancer, animal models.

[General anesthesia in mentally disabled patients undergoing dental surgery]. / Anestesia general en pacientes con discapacidad intelectual sometidos a cirugía dental.

OBJECTIVE: To describe the anesthetic technique used, the evaluation of airway patency, and the perioperative complications in patients with lower than average intelligence (mentally disabled) who are administered general anesthesia for dental surgery. MATERIAL AND METHODS: We carried out a prospective, descriptive, comparative study of mentally disabled ASA 2-3 patients. The patients were distributed in 2 groups: mild to moderate mental disability and severe to very severe mental disability. Induction was via intravenous or inhaled anesthesia depending on availability of venous access. Maintenance was with sevoflurane in oxygen and air at variable concentrations in order to maintain a bispectral index (BIS) between 40 and 60. Statistical comparisons were based on the chi2 test, the log-rank test and the t test. RESULTS: Forty-seven patients were enrolled. The anesthetic technique maintained hemodynamic stability in both groups. No statistically significant differences were found in Mallampati classification, Cormack-Lehane classification, or level of disability. The incidence of complications was higher in the group with more severe disability; the most common complication was difficult tracheal intubation. Bradycardia was the most common complication in the group with mild to moderate mental disability. CONCLUSIONS: The anesthetic technique used in this study proved to be safe and effective in this type of patient. A higher degree of mental disability led to less effective examination of the airway and more difficult direct laryngoscopy. BIS was as effective for monitoring in this population as it is in the general population.

Zein-polysaccharide nanoparticles as matrices for antioxidant compounds: A strategy for prevention of chronic degenerative diseases.

Oxidative Stress (OS) produces the formation of free radicals and other reactive oxygen and nitrogen species that are intimately involved in many diseases, especially Chronic Degenerative Diseases (CDD) such as cancer, diabetes, cardiovascular diseases, and obesity, among others. Thus, reactive compounds need to be quenched by antioxidants. The problems of these compounds include that they are susceptible to degradation, have low bioavailability, and can lose their bioactivity in the gastroIntestinal tract. Therefore, an alternative is encapsulation. Zein is a protein used in nanotechnology as a polymer matrix because it can encapsulate different compounds such as antioxidants to provide stability and control of the release. The disadvantage of zein as a delivery vehicle is that it is limited by the low stability of aggregation when suspended in water, in addition to the conditions of acid pH or that higher ionic strength tends to destabilize. To reduce these limitations, the incorporation of polysaccharides as a second polymer matrix can provide stability in zein nanoparticles. In this review, we discuss OS as a source of CDD, the role of antioxidants in the prevention of these diseases, and the preparation, characterization, and application of antioxidant-zein-polysaccharide particles as delivery systems as well as possible mechanisms to control CDD.

The magnitude of week 4 HCV RNA decay on pegylated interferon/ribavirin accurately predicts virological failure in patients with genotype 1.

BACKGROUND: Current stopping rules during pegylated interferon (peg-IFN)/ribavirin (RBV) treatment rely on week 12 HCV RNA response, but earlier identification of non-responders offers clinical and economic advantages. AIMS AND METHODS: To evaluate, among 129 HCV-genotype-1-infected, treatment-naive patients receiving peg-IFN/RBV, the feasibility of predicting treatment failure using receiver operating characteristics (ROC) curves after measuring week 4 HCV RNA decreases, and to assess baseline predictors of not achieving sustained virological response (SVR). RESULTS: Peg-IFN-alpha2b was used in 84.5% of patients. Fifty-three (41%) reached SVR. The best cutoff value of HCV RNA decrease at week 4 to predict non-SVR corresponded to 1 log10 IU/ml: sensitivity and negative predictive value: 100%; specificity: 64%; positive predictive value: 66%; ROC curve area: 0.91 (95% confidence interval [CI]: 0.86-0.96). By applying this threshold, treatment could have been discontinued at week 4 in 64% of virological non-responders (49/76). By univariate analysis, baseline HCV RNA > 800,000 IU/ml (P = 0.029), older age (P = 0.011), and higher aspartate aminotransferase (AST) levels (P = 0.005) or AST/alanine aminotransferase ratio values (P = 0.04) were associated with failure. After multivariate analysis, only baseline HCV RNA >800,000 IU/ml (odds ratio [OR]: 2.12; 95% CI: 1.005-4.488; P = 0.048) and higher AST levels (OR: 1.01; 95% CI: 1.003-1.024; P = 0.011) remained statistically significant. CONCLUSIONS: The lack of > or = log10 IU/ml decrease in baseline HCV RNA at week 4 was 100% predictive of treatment failure, independently associated with HCV RNA > 800,000 IU/ml and higher AST levels.

Ewing's sarcoma of the mandible: radiologic features with emphasis on magnetic resonance appearance.

Ewing's sarcoma is an uncommon malignancy that usually occurs in children. A case of Ewing's sarcoma of the mandible is presented, and the radiologic appearance is described, with special consideration given to the magnetic resonance imaging features.

Long term results of reconstruction plates in lateral mandibular defects. Revision of nine cases.

OBJECTIVE: Although microsurgical bone transplant is still the gold standard, mandibular reconstruction plates (MRP) were for several years considered a fast and safe way to restore mandibular continuity without using a bone graft. New plate designs with locking screws have been recently introduced, and these may overcome some of the complications related to previous designs. We review the results of mandibular reconstruction plates in our institution from 1991 to 1995. METHODS: The records of nine cancer patients who underwent lateral mandibular resections (with preservation of both condyle and symphysis) followed by reconstruction with a mandibular reconstruction plate, were retrospectively reviewed. Patients were treated between 1991 and 1995 with regular Synthes and Leibinger plates (without locking screws). Immediately after tumour resection, the bone defect was reconstructed with an MRP without bone grafting. Three cases required soft tissue coverage: two flaps and one buccal fat pad flap. RESULTS: There was immediate orocervical fistula in six cases, one of which required surgical closure; and late complications were common. One patient died due to distant metastasis 13 months after surgery without symptoms related to the plate. The remaining eight patients had their plates removed at between 9 and 52 months after reconstruction, due to screw loosening (four cases), plate exposure (one case), or both (three cases). CONCLUSION: Lateral mandibular reconstruction with non-locking screws and regular profile plates is no longer recommended. New plates with improved designs are currently available. Their low profile and locking screws are the usual characteristics of these new plates. More clinical experience is necessary before plate reconstruction can be recommended over microvascular bone transfer.

[Reconstruction of oral mucosa with a micro-vascularized fascia-cutaneous flap from the forearm]. / Reconstrucción de la mucosa yugal mediante colgajo microvascularizado fasciocutáneo antebraquial.

Epidermoid carcinoma of jugal mucosa is an aggressive tumor. Its treatment is based on broad excision and reconstruction in order to avoid fibrosis and restriction of mouth opening. Neck dissection and radiotherapy are indicated in selected cases. We display our experience with microvascularized flaps with the aim of preventing the flaws. We reconsider 8 patients (representing 10 flaps) handle in our Department. Besides we discuss other therapeutic alternatives after the growth's removal. The conclusion reached is that the mucovascularized forearm flaps give a great quantity of thin tissue and therefore so results to be the best option for the reconstruction of the jugal mucosa.

Clinical, radiological and therapeutic features of keratocystic odontogenic tumours: a study over a decade.

Factors associated with the potential for recurrence of keratocystic odontogenic tumours (KCOT) still remain to be clearly determined and no consensus exists concerning the management of KCOT. The purpose of this study was to evaluate different clinical factors associated with KCOT and its treatment methods. A retrospective review was performed of 55 cases treated from 2001 to 2010. Of the 55 cases, 27% were associated with an impacted or semi-impacted tooth. The majority of the lesions (82%) were located in tooth-bearing areas, and the overall mandibular to maxilla ratio of tumour occurrence was 5:1. The treatment options included enucleation, marsupialisation, or peripheral ostectomy, with or without the use of Carnoy´s solution. Recurrence was found in 14 cases (25%). No significant association was seen between recurrence and age, symptomatic cases, location of the lesion, or unilocular or multilocular appearance. The recurrence rate was higher in the group with tooth involvement, more marked in cases with third molar involvement. Statistical analysis showed a significant relation between recurrence and the type of treatment, with higher rates in cases treated with enucleation associated with tooth extraction. In our series, those cases with a closer relation with dental tissues showed a higher risk of recurrence, suggesting the need for a distinct classification for peripheral variants of KCOT. Key words:Keratocystic odontogenic tumour, Odontogenic keratocyst, Odontogenic cysts, Keratocyst, Carnoy's solution.

Prediction of acid hydrolysis of lignocellulosic materials in batch and plug flow reactors.

This study unifies contradictory conclusions reported in literature on acid hydrolysis of lignocellulosic materials, using batch and plug flow reactors, regarding the influence of the initial liquid ratio of acid aqueous solution to solid lignocellulosic material on sugar yield and concentration. The proposed model takes into account the volume change of the reaction media during the hydrolysis process. An error lower than 8% was found between predictions, using a single set of kinetic parameters for several liquid to solid ratios, and reported experimental data for batch and plug flow reactors. For low liquid-solid ratios, the poor wetting and the acid neutralization, due to the ash presented in the solid, will both reduce the sugar yield. Also, this study shows that both reactors are basically equivalent in terms of the influence of the liquid to solid ratio on xylose and glucose yield.