Archaeol Anthropol Sci
March 2025
Rock surface alterations due to weathering have often been used by archaeologists for creating chronologies, studying climatic conditions, and authenticating artifacts. Rock surface alterations are also important for identifying recycled artifacts through the presence of "double patina." In the surface archaeological deposits at Semizbugu (Saryarqa, Kazakhstan), rock surface weathering stages are used to chronologically categorize stone tool artifacts based on perceived associations between weathering characteristics and typology.
View Article and Find Full Text PDFThe purpose of this in vitro study was to investigate the release of silver and fluoride ions from caries lesions treated with silver diammine fluoride (SDF), with and without using a light-emitting diode (LED) curing light, the use of which increases silver penetration into the lesion. Eighteen extracted primary molars with natural caries lesions were divided into four groups: (1) one-minute SDF (n equals six); (2) 40-second SDF + 20-second LED (n equals six); (3) untreated control (n equals three); and (4) 20-second LED control (n equals three). Samples were immersed in artificial saliva for 0.
View Article and Find Full Text PDFThe bone organ is poorly represented in comparative research on mammalian mass-specific metabolic rates. As a first order attempt to remedy this, from the literature we collected mass-specific metabolic rates for all major organs except for the bone organ, and by subtraction infer the rate for the bone organ. The scaling relationships are given of each whole-organ mass-specific metabolic rate and of the relationship between whole-organ metabolic rate and body mass.
View Article and Find Full Text PDFObjectives: Age at death estimation is a key element to many research questions in biological anthropology, archeology, and forensic science. Dental cementum is a tissue of choice for the estimation of age at death in adult individuals as it continues deposition for the entirety of an individual's life. Previous works have devised regression formulas correlating cementum thickness to age at death.
View Article and Find Full Text PDFJ Clin Pediatr Dent
November 2023
This study investigated the effect of a light-emitting diode (LED) curing light on the depth of penetration of Silver Diamine Fluoride (SDF) into carious lesions. Twenty-four primary teeth with untreated caries lesions were allocated into groups and treated within 5 min after extraction: (1) n = 6 treated for 1 min with one drop of SDF followed by 10 sec rinse with tap water, (2) n = 6 treated for 10 sec with one drop of SDF and exposed to LED light for 20 sec (30 sec total SDF exposure) followed by 10 sec rinse with tap water, (3) n = 6 treated for 10 sec with one drop of SDF followed by a 10 sec rinse with tap water, (4) n = 3 untreated, and (5) n = 3 untreated but exposed to LED light for 20 sec. Samples were prepared, embedded, sectioned and silver penetration was measured using backscattered electron imaging in the scanning electron microscope and energy-dispersive X-ray spectroscopy analysis.
View Article and Find Full Text PDFBackground: While autografts to date remain the "gold standard" for bone void fillers, synthetic bone grafts have garnered attention due to their favorable advantages such as ability to be tailored in terms of their physical and chemical properties. Bioactive glass (BG), an inorganic material, has the capacity to form a strong bond with bone by forming a bone-like apatite surface, enhancing osteogenesis. Coupled with additive manufacturing (3D printing) it is possible to maximize bone regenerative properties of the BG.
View Article and Find Full Text PDFOvercoming the non-specificity of histological accentuated growth lines in hard tissues is an ongoing challenge. Identifying season at death and reproductive events has profound implications for evolutionary, ecological and conservation studies. Dental cementum is a mineralized tissue with yearly periodicity that continues deposition from tooth formation until death, maintaining a record spanning almost the entire life of an individual.
View Article and Find Full Text PDFExtracting life history information from mineralized hard tissues of extant and extinct species is an ongoing challenge in evolutionary and conservation studies. Primary lamellar bone is a mineralized tissue with multidien periodicity that begins deposition prenatally and continues until adulthood albeit with concurrent resorption, thus maintaining a record spanning several years of an individual's life. Here, we use field-emission scanning electron microscopy and energy-dispersive X-ray analysis to measure the relative concentrations of calcium, phosphorous, oxygen, magnesium and sodium in the femora of seven rhesus macaque with known medical and life-history information.
View Article and Find Full Text PDFThe evolution of modern human reproductive scheduling is an aspect of our life history that remains vastly uncomprehended. The present work aims to address this gap by validating a non-destructive cutting-edge methodology to infer adult life-history events on modern teeth with known life history and then applying it to fossil specimens. We use phase-contrast synchrotron X-ray microtomography to visualize the dental cementum of 21 specimens: nine contemporary humans; 10 Neanderthals from Krapina (Croatia, 130-120 kyr); one Neolithic from Ajmana (Serbia); and one Mesolithic from Vlasac (Serbia).
View Article and Find Full Text PDFJ Periodontal Implant Sci
December 2021
Purpose: The aim of this study was to evaluate the effects of locally delivered 1% alendronate (ALN) gel used as an adjunct to non-invasive periodontal therapy.
Methods: Ligature-induced periodontitis was performed in 96 rats. The ligature was tied in the cervical area of the mandibular left first molar.
Case: A 69-year-old woman underwent revision total knee arthroplasty for patellar component aseptic loosening. The periprosthetic tissue demonstrated histologic features of an adaptive immune response (aseptic lymphocyte-dominant vasculitis-associated lesion [ALVAL]). No particles of corrosion debris were identified.
View Article and Find Full Text PDFMany open questions in evolutionary studies relate to species' physiological adaptations, including the evolution of their life history and reproductive strategies. There are few empirical methods capable of detecting and timing physiologically impactful events such as weaning, parturition and illnesses from hard tissue remains of either extant or extinct species. Cementum is an incremental tissue with post eruption annual periodicity, which covers the tooth root and functions as a recording structure of an animal's physiology.
View Article and Find Full Text PDFThe elemental composition of freshwater and saltwater samples around the South Pacific island of Upolu, Samoa has been investigated together with other indicators of water quality. Up to 69 elements from Li (3) to U (92) are measured in each sample, analyzed by Mattauch-Herzog-inductively coupled plasma-mass spectrometry (MH-ICP-MS). One hundred and seventy-six samples were collected from surface freshwater sources (24 rivers, two volcanic lakes, one dam) and from seawater sources from the surface to 30 m depth (45 inner reef, reef, and outer reef locations) around Upolu Island, including river mouths and estuaries.
View Article and Find Full Text PDFRecent studies have provided great insight into hominin life history evolution by utilizing incremental lines found in dental tissues to reconstruct and compare the growth records of extant and extinct humans versus other ape taxa. Among the hominins, studies that have examined Retzius periodicity (RP) variation have come to contradictory conclusions in some instances. To clarify RP variation among hominins and better place this variation in its broader evolutionary context, we conduct the most comprehensive analysis of published RP values for hominins and great apes to date.
View Article and Find Full Text PDFAims: To measure the number of days of enamel formation between periodic striae of Retzius growth lines, the Retzius periodicity (RP), and to compare this multi-day, or multidien rhythm, to body height and weight among people from Beijing, China and Lhasa, Tibet/China.
Subjects And Methods: Subjects requiring dental extractions from clinics in Beijing, China ( = 338) and Lhasa, Tibet/China ( = 227) provided a tooth and body size information. Multiple observers examined histological sections of the teeth and recorded RP.
Statement Of Problem: There is little evidence on how the multiple layers of zirconia (ZrO) or glazed material will affect the shear bond strength (SBS) of different resin cements.
Purpose: The purpose of this in vitro study was to compare the SBS of 2 resin cements with the different layers of a monolithic polychromatic ZrO ceramic, both glazed and nonglazed, and a lithium disilicate (LDS) ceramic.
Material And Methods: One hundred and sixty-eight composite resin cylinders and 48 monolithic polychromic ZrO plates were prepared.
The life history pattern of recent humans is uniquely derived in many of its aspects including an extended post-reproductive lifespan combined with short interbirth intervals. A number of theories have been proposed to explain the evolution of this unusual pattern. However most have been difficult to test due to the fragmentary nature of the hominin fossil record and the lack of methods capable of inferring such later life history events.
View Article and Find Full Text PDFCharacterizing dental development in fossil hominins is important for distinguishing between them and for establishing where and when the slow overall growth and development of modern humans appeared. Dental development of australopiths and early Homo was faster than modern humans. The Atapuerca fossils (Spain) fill a barely known gap in human evolution, spanning ~1.
View Article and Find Full Text PDFDeeper or more 'severe' linear enamel hypoplasia (LEH) defects are hypothesized to reflect more severe stress during development, but it is not yet clear how depth is influenced by intrinsic enamel growth patterns. Recent work documented inter- and intraspecific differences in LEH defect depth in extant great apes, with mountain gorillas having shallower defects than other taxa, and females having deeper defects than males. Here, we assess the correspondence of inter- and intraspecific defect depth and intrinsic aspects of enamel growth: enamel extension rates, outer enamel striae of Retzius angles, and linear enamel thickness.
View Article and Find Full Text PDFCells are transplanted to regenerate an organs' parenchyma, but how transplanted parenchymal cells induce stromal regeneration is elusive. Despite the common use of a decellularized matrix, little is known as to the pivotal signals that must be restored for tissue or organ regeneration. We report that Alx3, a developmentally important gene, orchestrated adult parenchymal and stromal regeneration by directly transactivating Wnt3a and vascular endothelial growth factor.
View Article and Find Full Text PDFStore-operated Ca entry (SOCE) channels are highly selective Ca channels activated by the endoplasmic reticulum (ER) sensors STIM1 and STIM2. Their direct interaction with the pore-forming plasma membrane ORAI proteins (ORAI1, ORAI2, and ORAI3) leads to sustained Ca fluxes that are critical for many cellular functions. Mutations in the human gene result in immunodeficiency, anhidrotic ectodermal dysplasia, and enamel defects.
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