Cavity Density Research Articles

Habitat use of Bechstein’s Bat (Myotis bechsteinii) and woodpeckers reveals the importance of old-growth features in European beech forests

Old-growth forests provide valuable habitats for bat and woodpecker species worldwide. However, the abundance of old-growth related habitat features is frequently reduced in managed forests. Bechstein’s Bat (Myotis bechsteinii, Kuhl 1817) is globally restricted to old-growth deciduous forests in Europe and therefore a species of high European conservation priority. Since the species prefers woodpecker cavities for roosting, woodpeckers are keystone species for Bechstein’s Bat. We surveyed woodpecker activity and forest structural features within 16 roost sites of Bechsteińs Bat and a random sample from the surrounding managed forest within the centre of the global distribution of Bechsteińs Bat. We found above-average quantity of old-growth related habitat features in the roost sites of Bechstein’s Bat. Five of six occurring woodpecker species revealed significantly higher densities in the roost sites of Bechstein’s Bat, demonstrating a distinct preference of the woodpeckers and the bat in managed forests for old, deciduous stands with high basal areas of large living trees (DBH > 50 cm), bearing deadwood structures and highest available tree cavity densities. Furthermore, when comparing the direct surroundings of roost trees to their wider surroundings (16 ha), cavity density and other old-growth features reached their maxima in the direct surroundings of roost trees (mean = 19.3 cavities ha−1), demonstrating a distinct habitat selection of Bechsteińs Bat for patches with maximum available cavity density on large and fine spatial scale. We found a close relation between the basal area of trees with limb break offs (>20 cm base diameter) and tree cavity density, which leads us to the conclusion that specifically injured but still vital, large trees play a major role for the development and long-term persistence of tree cavities. Finally, our analyses revealed a threshold of 20 (DBH > 50 cm) or 10 (DBH > 70 cm) large deciduous trees bearing deadwood structures per ha to fulfil the minimum habitat requirements of the woodpeckers and Bechstein’s Bat. Obviously, Bechsteińs Bat and the associated woodpeckers explicitly selected forest patches, which most closely resembled primeval forest benchmarks, emphasising the importance of maintaining and developing forest patches, providing the mentioned habitat features within managed forests.

PENURUNAN OPRIT JEMBATAN SEMARANG LINGKAR UTARA DAN JEMBATAN KALI JAJAR DEMAK JAWA TENGAH DENGAN PRE-FABRICATED VERTICAL DRAIN

Construction on soft soil, often creates problems. The Semarang North Ring Bridge and Kali Jajar Bridge are the Recent soft Marine Alluvium zones located in the Pantura area which have very soft soil characteristics with a depth of more than -30.0 meters this has resulted in a very large settlement due to very small grains, flood, rob, pore water pressure increases so that the shear strength of the soil will be small, the compression is large and the permeability coefficient is small so that if the construction load exceeds the critical bearing capacity, the damage to the foundation soil will occur. To get the increase in soil bearing capacity, it can be achieved by changing the properties of the soil from the shear angle (f), cohesion (c) and unit weight (g). The settlement can be reduced by increasing the cavity density from the compression of the soil particles (Wesley, 1977). Soil improvement takes a long time, aiming to increase shear resistance so that it requires a fast time in this case is to use Pre-Fabricated Vertical Drain (Bowles 1981). The results of the analysis of the pattern of decline and the effectiveness of the use of PVD (pre-fabricated vertical drain) at the Oprit Bridge in the two research locations have the same decrease in the range of the same heap height at (H = 4 meters) there is a decrease of 117.53 cm at 64 months on the bridge. Kali Jajar (STA. 3 + 200) and there was a decrease of 268.94 cm at 37 months at the Semarang North Ring Bridge

Mechanistic insight into the dispersion behavior of single platinum atom on monolayer g-C3N4 in single-atom catalysts from density functional theory calculations

Single-atom catalysts (SACs) are an effective strategy for the efficient and low-cost utilization of noble metals. However, it remains a huge challenge to obtain atomically dispersed SACs. In this work, the dispersion behavior of single platinum atoms on pristine monolayer g-C3N4 has been investigated by DFT calculations. The calculation results show that the diffusion of single atom Pt on pristine monolayer g-C3N4 has characteristics of anisotropy. More importantly, the migration and aggregation of single atom Pt within the global scope of monolayer g-C3N4 can be effectively avoided, while in the local scope, the migration of single atom Pt is easy, and single atom Pt clustering is inevitable. Significantly, it can be predicted that stable SACs can be synthesized when the coverage of single atom Pt is less than the density of six-fold cavity. Moreover, it is found that the Pt clusters confined in the six-fold cavity of monolayer g-C3N4 are very stable and difficult to migrate on monolayer g-C3N4. And, the larger the size of Pt clusters confined in monolayer g-C3N4, the more difficult to separate a Pt atom from the Pt clusters. These results indicate that the Pt clusters confined in monolayer g-C3N4 have an effective Ostwald ripening mechanism.

Influence of logging on nest density and nesting microsites of cavity-nesting birds in the subtropical forests of the Andes

Abstract Birds select nesting sites with certain characteristics associated with tree age and species that help to prevent or reduce the risk of clutch loss due to predation or unfavourable weather conditions. Logging may reduce the availability of trees and their related features that may be important for cavity nesters. Thus, the aim of this study is to evaluate the effect of logging on nest density, nesting microsite and nest success of cavity nesting birds at Piedmont forests of northwestern Argentina. We monitored these variables at different logged and unlogged sites during four consecutive reproductive seasons and analysed them using univariate analysis and generalized linear models. The main results indicate that logging reduces nest density and changes the characteristics of the nesting microsites. We found that nest success was greater in cavities located higher above the ground and found no evidence of lower nest success at logged sites. This study suggests the need for forest management actions aimed at increasing nesting sites for cavity-nesting birds. For this purpose, management should be focused on the retention of old trees with a diameter >50 cm (both living and dead). The use of reduced-impact logging techniques or forest certifications (e.g. Forest Stewardship Council) could provide alternatives in subtropical forests, as these forestry practices can ensure tree abundance and richness, providing features suitable for cavity-nesting birds (e.g. tree diameter, cavity size and height).

Abundant Natural Cavities in a Deciduous Forest Leads to a Lack of Nest-Box Occupancy by Northern Saw-Whet Owls

Nest boxes are commonly used for species that utilize tree cavities, including small owls. Boxes were installed in 2011 to facilitate study of Northern Saw-whet Owls in Pennsylvania. We checked the 11 boxes that remained in 2020 after a hiatus of 8 years and found 3 rodent nests, but no evidence of owl usage. Playbacks revealed owls were present at 8 of 11 boxes checked. Cavity surveys yielded an average of 7.7 large cavities within 50 m of each box; extrapolation of cavity densities to a minimal territory size of 150 ha suggested that suitable cavities are an abundant, non-limiting resource here. Cavity abundance was likely a consequence of beech bark disease complex having recently top-killed most large American Beech trees locally, providing abundant resources for excavating woodpeckers. Assessing cavity abundance should be an essential first step for any management project involving cavity-nesting birds, and nest boxes should be used only in situations where cavities appear to be limited.

Foreshock Cavities: Direct Transmission Through the Bow Shock

AbstractGlobal hybrid code simulations predict enhanced densities and magnetic field strengths not only in foreshock compressional boundaries on the flanks of the steady‐state dayside foreshock under near‐radial IMF conditions but also on the edges of the traveling foreshock cavities formed when slabs of interplanetary magnetic field (IMF) lines connect to the bow shock. The simulations predict only modest velocity or temperature perturbations attending the foreshock compressional/cavity boundaries. However, they predict pronounced flow enhancements and depressed temperatures accompanying the enhanced densities and magnetic field strengths on foreshock compressional/cavity boundaries transmitted into the magnetosheath. Many of these properties are similar to those of magnetosheath jets, previously attributed to processes occurring at locations where the solar wind flow makes a grazing encounter with a locally oblique bow shock. Simultaneous THEMIS observations upstream and downstream from the Earth’s bow shock from 1430 to 1630 UT on June 14, 2007 confirm simulation predictions for the direct transmission of foreshock cavities into the magnetosheath. Foreshock cavity density and magnetic field strength perturbations diminish very rapidly with distance upstream from the bow shock.

Evaluation of spheroidized tungsten carbide powder produced by induction plasma melting

Tungsten carbide is a fine grey powder. It can be formed into shapes by compacting with the addition of a binder. Spherical particles are generally preferred in additive manufacturing as they pack together more efficiently than non-spherical particles, promoting a uniform powder bed density, better flowability, and elimination of internal cavities and fractures, resulting in a better quality of final product. The particle shape of powders can be transformed into spherical through the process of spheroidization. However, due to its high melting point, tungsten carbide could be difficult to spheroidize. Tungsten carbide was spheroidized using an inductively coupled radio frequency plasma at various plate powers between 9 and 15 kW. The influence of additional H2 in the sheath gas on the chemical composition of the tungsten carbide product was also investigated by means of XRD, which indicated that WC is converted to W2C at higher H2 concentrations. Optical analysis of SEM micrographs indicated that the spheroidization ratio increased with increased plasma energy.

Integration of satellite-based A-DInSAR and geological modeling supporting the prevention from anthropogenic sinkholes: a case study in the urban area of Rome

This paper presents a methodology tuned to support the management of underground pipelines (sewer and aqueduct networks) in Rome, often threatened by the sudden formation of sinkholes related to the upward migration of existing underground cavities. The methodology integrates data coming from the assessment of susceptibility to sinkhole formation and the advanced processing of satellite-based SAR imagery. The former, performed through the multivariate logistic regression technique, relies on a detailed database of stratigraphic and other thematic (i.e. sinkhole inventory and density of underground cavities) information. A-DInSAR processing of satellite images, for which we developed on-purpose algorithms to filter only data relevant for the process under study, allowed us to provide density maps of subsiding reflectors whose likelihood to be precursors of sinkhole collapses is rated based on the integration with the susceptibility map. The procedure is addressed to point out potentially critical ‘hotspots’ that the company managing the underground networks should pay attention to by means of further detailed investigations. Recent (i.e. occurred after the finalization of the products shown in this paper) sinkholes validated the reliability of the procedure adopted, whose strength is the data fusion able to produce refined and focused information starting from independent and more generic datasets.

Helium Causing Disappearance of ½ a<111> Dislocation Loops in Binary Fe-Cr Ferritic Alloys

Single and dual-beam self-ion irradiations were performed at 500 °C on ultra-high purity Fe14%Cr alloy to ~0.33 displacements-per-atom (dpa), and 0 or 3030 atomic-parts-per-million (appm) helium/dpa, respectively. Using transmission electron microscopy, we reveal that helium can drastically modify the dislocation loop Burgers vector in Fe-Cr alloys. Helium co-implantation caused complete disappearance of a/2 type dislocation loops, and the microstructure consisted of only a loops. Conversely, a/2 type loops were predominant without He co-implantation. The total loop density remained largely unaffected. The results strikingly contrast literature asserting that helium stabilizes a/2 type loops in bcc Fe alloys, based on low temperature irradiations. Collectively analyzing the results with literature suggests that the small positive interaction between helium and self-interstitial atoms (SIA) in Fe, predicted by atomistic simulations, maybe insufficient to holistically explain the dislocation loop microstructure development in presence of helium. Helium-SIA positive binding inadvertently implies elevated a/2 loop fraction and higher loop densities that the present results contradict. Helium induced high cavity density causing a preferential loss of highly glissile clusters, leaving the matrix saturated with type clusters is proposed as a potential mechanism. Further, the in-situ irradiations combined with Burgers vector analysis strengthened the evidence of Cr-induced dislocation loop mobility reduction that appears to stabilize the a/2 type loops and causes higher loop densities in Fe-Cr alloys.

Abstract 13949: Quantitative Assessment of the Left Atrial Appendage as a More Reliable Method of Thromboembolic Risk Stratification

Introduction: Assessment of the left atrial appendage (LAA) in patients with atrial fibrillation (AF) undergoing cardioversion for thromboembolic risk stratification is inherently qualitative. Oftentimes, interobserver assessment may disagree, leading to differences in risk stratification and patient management. We propose a novel method of quantitative LAA assessment and examine its predictive value for future thromboembolic events. Hypothesis: Evaluation of LAA using ImageJ pixel density quantification software in patients with AF will be superior to qualitative assessment by expert readers in assessing and predicting future thromboembolic risk. Methods: A total of 124 patients (mean age 59 ± 13 years, 70% male) undergoing transesophageal echocardiography to exclude LAA thrombus prior to radiofrequency pulmonary vein isolation or electrical cardioversion for AF were retrospectively studied. LAA were examined by two expert readers and identified as thrombus ( n = 9), sludge ( n = 11), spontaneous echocontrast ( n = 90), or normal ( n = 138). LAA were then separately examined using ImageJ to calculate a gain-independent ratio between the average pixel density of the LAA cavity and the average pixel density of the LAA wall (C/W ratio). Results: There was significant disagreement between the two expert readers in LAA assessment (weighted Kappa 0.510, p < 0.0001). Qualitative LAA analysis was significantly related with C/W ratio ( p < 0.0001) and thromboembolic events ( p < 0.0002). C/W ratio was also significantly related with thromboembolic events (OR 1.60, 95% CI 1.095 - 2.347, p < 0.0152). According to Area Under the Curve (AUC) of the ROC curve, C/W ratio (AUC 0.73, 95% CI 0.60 - 0.86) was a more reliable predictor for future thromboembolic when compared to qualitative LAA assessment (AUC 0.72, 95% CI 0.53-0.90). Conclusions: Quantitative LAA assessment using the C/W ratio provided by ImageJ software is more reliable than qualitative assessment by expert readers for identifying future thromboembolic events while reducing reader variability.

Normal vector approach to Fourier modal scattering from planar periodic photonic structures

Fourier modal expansion techniques are very well suited for electromagnetic (EM) scattering in planar periodic stratified media. These techniques expand the transverse EM fields in Bloch modes in each strata unit-cell, but do not rigorously enforce EM boundary conditions at interior material interfaces which gives rise to slow convergence of the polarized S-matrix values with increasing Fourier series truncation order. We present a normal vector (NV) Fourier modal scattering approach that uses the gradient of the real permittivity in the unit-cell to generate a local NV resulting in anisotropic eigenmodes of Maxwell's equations that satisfy interior boundary conditions. The convergence of this expansion method is examine numerically for our analytic NV derived from planar primitive geometry elements for various example structures. The Fourier modal NV method is then derived for the planar cavity boundary value problem and the cavity eigenmodes and density of states is determined from the analytic continuation of the secular determinant. A complete scattering method for highly dispersive materials and sub-wavelength structures has been presented that is adaptable to planar EM cavity problems using fluctuation electrodynamics formalism.

Application of a PhotoThermal model for container-grown conifer seedling production

This study applied a total energy approach to model seedling growth for container-grown loblolly pine (Pinus taeda L.). Seedlings were grown in three container stocktypes representing a range of cavity volume and density patterns. These seedlings were grown under both controlled greenhouse and outside compound environmental conditions under well-defined cultural conditions. Models for temperature and light ranges were created from work on the ecophysiological performance and morphological development of loblolly pine to these atmospheric conditions. A PhotoThermal data set was created by generating hourly averages of these two environmental variables during the growing season. Light and temperature data were integrated, each weighted equally, into PhotoThermal hours (PTH) to assess the crop growth response. Loblolly pine seedling growth in both the greenhouse and outside compound was directly related to PTH. Seedling growth was also related to the container type with the largest cavity volume and lowest cavity density having the greatest growth per PTH. Application of the PhotoThermal model is discussed for growing seedlings in an operational program having multiple production steps, delivery dates and nursery locations.

High-temperature effects on creep-fatigue interaction of the Alloy 709 austenitic stainless steel

High-temperature creep-fatigue behavior of the Alloy 709 is investigated by performing strain-controlled creep-fatigue tests at 650 °C and 750 °C with tensile hold times of 0, 60, 600, 1,800 and 3,600 s at 1% strain range and strain rate of 2 × 10−3 s−1. Results revealed that creep-fatigue life at 650 °C fluctuates due to Dynamic Strain Aging (DSA) during hold periods. Linear damage summation (LDS) was employed to construct the creep-fatigue interaction diagram of the alloy at different loading conditions. An increased density of cracks and creep cavities is observed at 750 °C with less dislocation density compared to 650 °C.

Evaluation of bone healing of odontogenic maxillary cystic defects grafted with hemihydrated calcium sulphate granules Versus biphasic calcium phosphate granules: A Randomized Controlled Clinical Trial

Objectives: This study aims to compare between the effect of hemihydrated calcium sulphate bone graft granules and biphasic calcium phosphate granules on bone healing of maxillary cystic defects. Patients and methods: Twenty patients (15 males, 5 females; age range, 16 to 40 years with an average of 25 years) with maxillary cystic lesions were included in this prospective, comparative study. Patients were randomized into two groups as group 1 in which the cystic defects were grafted with hemihydrated calcium sulphate bone graft granules (n=10) and group 2 in which the cystic defects were treated with biphasic calcium phosphate granules(SYMBIOS) (n=10). Postoperative assessments were performed for both groups, clinically through detection of any signs of infection, inflammation, or graft rejection; and radiographically. Radiographic assessment was performed by using cone beam computed tomography (CBCT) preoperative and at 6 months postoperatively for measurement of relative bone density and dimensional changes of the cystic cavity. Results: The radiographic results demonstrated a statistical insignificant difference between the medians (IQR) of relative dimension and density changes of cystic defects in both groups after 6 months. Conclusion: Both bone grafts granules have the same effects on bone filling of cystic defects. Also, both grafts are similar in reducing dimensions of cystic cavities during healing.

Comparison of Test Setups for the Experimental Evaluation of the Primary Fixation Stability of Acetabular Cups.

Sufficient primary fixation stability is the basis for the osseointegration of cementless acetabular cups. Several test methods have been established for determining the tilting moment of acetabular press-fit cups, which is a measure for their primary fixation stability. The central aim of this experimental study was to show the differences between the commonly used lever-out test method (Method 1) and the edge-load test method (Method 2) in which the cup insert is axially loaded (1 kN) during the tilting process with respect to the parameters, tilting moment, and interface stiffness. Therefore, using a biomechanical cup block model, a press-fit cup design with a macro-structured surface was pushed into three cavity types (intact, moderate superior defect, and two-point-pinching cavity) made of 15 pcf and 30 pcf polyurethane foam blocks (n = 3 per cavity and foam density combination), respectively. Subsequently, the acetabular cup was disassembled from the three artificial bone cavities using the lever-out and the edge-load test method. Tilting moments determined with Method 1 ranged from 2.72 ± 0.29 Nm to 49.08 ± 1.50 Nm, and with Method 2, they ranged from 41.40 ± 1.05 Nm to 112.86 ± 5.29 Nm. In Method 2, larger areas of abrasion were observed in the artificial bone cavity compared to Method 1. This indicates increased shear forces at the implant–bone interface in the former method. In conclusion, Method 1 simulates the technique used by orthopedic surgeons to assess the correct fit of the trial cup, while Method 2 simulates the tilting of the cup in the acetabular bone cavity under in situ loading with the hip resultant force.

Large trees and decay: Suppliers of a keystone resource for cavity‐using wildlife in old‐growth and secondary Andean temperate forests

AbstractTree cavities are a keystone resource for many wildlife species worldwide. In Andean temperate forests of South America, many species of birds, mammals and reptiles use cavities to achieve their life history requirements. However, information on cavity supply and drivers of cavity production in these forests remains largely undocumented. We examined the patterns of tree‐cavity supply in successional native forests, exploring the potential drivers of cavity occurrence and relative abundances in Andean temperate ecosystems of southern Chile. In 10 forest stands, we established 369 vegetation plots and measured 7951 trees. For each tree, we recorded the species and measured the diameter at breast height (DBH), decay class and number of cavities. While tree density was much higher in secondary than in old‐growth forest stands, the density of nonexcavated cavities was higher in old‐growth than in secondary forests. Cavity occurrence and relative abundances (number of cavities per tree) were higher in large decaying and standing dead trees (i.e. habitat legacies) than in young healthy trees. Importantly, DBH and decay had a stronger influence on the supply of nonexcavated than excavated cavities. Our results highlight the importance of old‐growth forest stands, tree decay processes and habitat legacies for securing a continuous supply of a keystone habitat resource for tree cavity‐using wildlife in a global biodiversity hotspot of South America.Abstract in Spanish is available with online material.

The role of local cavity tree density in the selection of den sites by female fishers (Pekania pennanti) in northern Minnesota

Although several studies have evaluated fisher (Pekania pennanti (Erxleben, 1777)) selection of den structures across their natural range, the role of other nearby trees with suitable cavities that can be used by female fishers for subsequent maternal dens has not been explored. We used conditional logistic regression to describe selection of natal and maternal dens by female fishers in northern Minnesota, United States, and to determine if the density of other cavity trees surrounding a specific tree influences this selection. Our results indicate that cavity density was an important predictor of whether a tree was used as a den site by female fishers. The apparent condition (i.e., live, declining, or dead) and diameter at breast height of the cavity tree itself were also important for selection. These results affirm the need to retain large-diameter cavity trees, illustrate the potential benefits of retaining them in high-density patches, and caution against creating a landscape with highly dispersed denning options.

Intramedullary Canal-creation Technique for Patients with Osteopetrosis

ABSTRACTAimWe present details of a surgical technique to create an intramedullary canal to allow intramedullary fracture fixation in patients with osteopetrosis. Clinical cases are used to facilitate the description.BackgroundOsteopetrosis is a rare, hereditary condition characterised by hard, brittle, “marble bone;” primarily due to osteoclast dysfunction. Patients are prone to fractures and subsequently nonunions, periprosthetic fractures, and metal-ware failure are commonly seen. Due to the increased bone density, deformity, and obliteration of the medullary cavity, fracture fixation is also technically demanding.TechniqueCreation of a medullary canal allows the use of intramedullary fixation rather than plate and screws for long-bone fractures.Key factors:A new sharp drill bit should be used for each case as blunt drills are more likely to break.Bone is drilled in a pulsatile fashion, with withdrawal every 2–4 seconds for bone swarf to be removed.Constant cooling of the drill bit with saline to help prevent bone necrosis and drill breakage.Regular exchanging of drill bit sizes to expand the canal. The smaller drills start the canal and are used to direct progress. Sequential expansion during canal creation is preferred.Regular use of orthogonal radiographs to ensure correct canal positioning and prevent perforation.ConclusionThe creation of an intramedullary canal allows intramedullary fracture fixation. In our experience, this technique gives the orthopaedic surgeon a safe and effective method for treating long-bone fractures in patients with osteopetrosis.Clinical relevanceFractures and nonunions in patients with osteopetrosis are difficult to manage; and by detailing this technique, a further option is now available for surgeons when deciding upon fixation method.How to cite this articleKent J, Ferguson D. Intramedullary Canal-creation Technique for Patients with Osteopetrosis. Strategies Trauma Limb Reconstr 2019;14(3):155–162.

Lattice-gas Monte Carlo study of sI clathrate hydrates of ethylene: Stability analysis and cell distortion

In this paper, a two-dimensional lattice-gas model is applied to study the stability and lattice distortion of sI clathrate hydrates of ethylene. Two levels of approximation are considered for the lateral interactions between the adsorbed molecules. By using Monte Carlo simulations, adsorption isotherm (coverage of the cavities as a function of the chemical potential), degree of deformation of the sI structure, and free energy of the adsorbed phase are obtained. A direct relationship between cell distortion and cell occupancy is observed. In addition, the minimum distortion coincides with the minimum value of the free energy. Accordingly, the stability phase diagram can be calculated from the values of the chemical potential at the minimum deformation. The obtained results indicate that the most stable condition of the system occurs for values of the cavity density ranging between 0.35 and 0.4. Finally, MC results are compared with data from experiments and more complex simulations.

Controlled release of anti-cancer drug from the shell and hollow cavities of poly(N-isopropylacrylamide) hydrogel particles synthesized via reversible addition-fragmentation chain transfer polymerization

Temperature-responsive poly(N-isopropylacrylamid) (PNIPAAm) hydrogels with two different crosslinking densities were coated on silica nanoparticles via surface-initiated reversible addition-fragmentation chain transfer network formation method in an inverse emulsion medium. The temperature-responsive hollow hydrogel particles were also prepared by etching of the silica cores using hydrofluoric acid. The hybrid and hollow hydrogel particles were used as doxorubicin (DOX) delivery systems. The synthesis process was evaluated by proton magnetic nuclear resonance and Fourier-transform infrared spectroscopies, thermogravimetric analysis, and scanning and transmission electron microscopies. Dynamic light scattering and turbidimetry by UV–vis spectroscopy were also used to study responsivity of the hybrid and hollow PNIPAAm hydrogels to temperature. Gel collapse temperature (GCT) of the hydrogels was studied using UV transmittance curves. UV transmittance and the GCT value of the hollow hydrogels were higher than the hybrid samples. The hollow hydrogel particles with higher crosslinking density showed higher hydrodynamic diameter (Dh) at temperatures of above the GCT, whereas the hollow cavity and lower crosslinking densities resulted in higher Dh at temperatures below GCT. Release of DOX from the hybrid and hollow hydrogel particles with two different crosslinking densities was investigated by using UV–vis spectroscopy at below and above GCT of the hydrogel particles (25 and 45 °C, respectively). The hollow particles with low crosslinking density showed the lowest release percent due to its higher loading capacity. In addition, the DOX release percent was reduced by increasing temperature from 25 to 40 °C.