Upgrading recovered carbon black (rCB) from industrial-scale end-of-life tires (ELTs) pyrolysis to activated carbons: Material characterization and CO2 capture abilities

The current study presents for the first time how recovered carbon black (rCB) obtained directly from the industrial-scale end-of-life tires (ELTs) pyrolysis sector is applied as a precursor for activated carbons (ACs) with application in CO2 capture. The rCB shows better physical characteristics, including density and carbon structure, as well as chemical properties, such as a consistent composition and low impurity concentration, in comparison to the pyrolytic char. Potassium hydroxide and air in combination with heat treatment (500-900 °C) were applied as agents for the conventional chemical and physical activation of the material. The ACs were tested for their potential to capture CO2. Ultimate and proximate analysis, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), Raman spectroscopy, thermogravimetric analysis (TGA), and N2/CO2 gas adsorption/desorption isotherms were used as material characterization methods. Analysis revealed that KOH-activated carbon at 900 °C (AC-900K) exhibited the highest surface area and a pore volume that increased 6 and 3 times compared to pristine rCB. Moreover, the AC-900K possessed a well-developed dual porosity, corresponding to the 22% and 78% of micropore and mesopore volume, respectively. At 0 °C and 25 °C, AC-900K also showed a CO2 adsorption capacity equal to 30.90 cm3/g and 20.53 cm3/g at 1 bar, along with stable cyclic regeneration after 10 cycles. The high dependence of CO2 uptake on the micropore volume at width below 0.7-0.8 nm was identified. The selectivity towards CO2 in relation to N2 reached high values of 350.91 (CO2/N2 binary mixture) and 59.70 (15% CO2/85% N2).

MoxC Heterostructures as Efficient Cocatalysts in Robust MoxC/g-C3N4 Nanocomposites for Photocatalytic H2 Production from Ethanol

In this work, we studied new materials free of noble metals that are active in photocatalytic H2 generation from ethanol aqueous solutions (EtOHaq), which can be obtained from biomass. MoxC/g-C3N4 photocatalysts containing hexagonal (hcp) Mo2C and/or cubic (fcc) MoC nanoparticles on g-C3N4 nanosheets were prepared, characterized, and evaluated for photocatalytic hydrogen production from EtOHaq (25% v/v). Tailored MoxC/g-C3N4 nanocomposites with MoxC crystallite sizes in the 4-37 nm range were prepared by treatment with ultrasound of dispersions containing MoxC and g-C3N4 nanosheets, formerly synthesized. The characterization of the resulting nanocomposites, MoxC/g-C3N4, by different techniques, including photoelectrochemical measurements, allowed us to relate the photocatalytic performance of materials with the characteristics of the MoxC phase integrated onto g-C3N4. The samples containing smaller hcp Mo2C crystallites showed better photocatalytic performance. The most performant nanocomposite contained nanoparticles of both hcp Mo2C and fcc MoC and produced 27.9 mmol H2 g-1 Mo; this sample showed the lowest recombination of photogenerated charges, the highest photocurrent response, and the lowest electron transfer resistance, which can be related to the presence of MoC-Mo2C heterojunctions. Moreover, this material allows for easy reusability. This work provides new insights for future research on noble-metal-free g-C3N4-based photocatalysts.

Chemical Activation of Banana Peel Waste-Derived Biochar Using KOH and Urea for CO2 Capture

This article describes the synthesis and characterization of porous carbon derived from waste banana peels by chemical activation with KOH or by activation KOH and urea modification. The as-synthesized samples were carefully characterized by various techniques. The prepared carbonaceous materials possess highly developed micropore and mesopore structures and high specific surface area (up to 2795 cm2/g for materials synthetized with KOH and 2718 cm2/g for activated carbons prepared with KOH and urea). A series of KOH-activated samples showed CO2 adsorption at 1 bar to 5.75 mmol/g at 0 °C and 3.74 mmol/g at 25 °C. The incorporation of nitrogen into the carbon sorbent structure increased the carbon uptake capacity of the resulting materials at 1 bar to 6.28 mmol/g and to 3.86 mmol/g at 0 °C and 25 °C, respectively. It was demonstrated that treatment with urea leads to a significant increase in nitrogen content and, consequently, CO2 adsorption, except for the material carbonized at 900 °C. At such a high temperature, almost complete decomposition of urea occurs. The results presented in this work could be used in the future for utilization of biomass such as banana peels as a low-cost adsorbent for CO2 capture, which could have a positive impact on the environment and human health protection.

Functional Activated Biocarbons Based on Biomass Waste for CO2 Capture and Heavy Metal Sorption

Inexpensive porous activated biocarbons were prepared from biomass and agriculture waste following the method of thermal and hydrothermal carbonization and activation with superheated water vapor. The activated biocarbons were characterized by nitrogen adsorption-desorption at 77 K, SEM, XRD, Raman spectrometry, FTIR spectroscopy, determination of particle size, and elemental composition by XRF. The specific surface area was in the range of 240-709 m2/g, and the total pore volume was from 0.12 to 0.43 cm3/g. The percentage of microporosity in activated biocarbons was 89-92%. These activated biocarbons have been used for CO2 and heavy metal sorption. Activated biocarbons based on pine cones and birch prepared by thermal carbonization and activation with superheated water vapor had the highest ability to capture CO2 and amounted to 6.43 and 6.00 mmol/g at 273 K, as well as 4.57 and 4.22 mmol/g at 298 K, respectively. The best activated biocarbon was characterized by unchanged stability after 30 adsorption and desorption cycles. It was proved that the adsorption of CO2 depends on narrow micropores (<1 nm). Activated biocarbons have also been analyzed as effective adsorbents for removing Cu2+, Zn2+, Fe2+, Ni2+, Co2+, and Pb2+ ions from aqueous solutions. Activated biocarbons are effective adsorbents for the removal of lead and zinc ions from aqueous solutions.

Biomass-based activated carbons produced by chemical activation with H3PO4 as catalysts for the transformation of α-pinene to high-added chemicals

In the era of ecology and careful care for the environment, it becomes important to use renewable raw materials of plant origin, which are often more easily available and cheaper. One of the important and rapidly developing directions of research are works related to the use of waste plant biomass; an example of this trend is the production of activated carbons from food industry waste. One of the examples of the application of derived from biomass activated carbons can be using them as catalysts for the isomerization of terpene compounds. Carbons based on waste biomass are characterized by the minimal amount of waste formation during their manufacture, and their use in the isomerization reaction allows to obtain high conversion of organic raw material and high selectivities of transformation to the desired products, making these carbons environmentally friendly substitutes for the catalysts used usually in this process. In this work, obtained carbonaceous catalysts were tested in the process of isomerization of α-pinene to high value chemicals (mainly camphene and limonene). Under the most favorable conditions (activated carbon from sunflower husks content in reaction mixture 5 wt%, temperature 180 °C, and reaction time 100 min), α-pinene was completely converted (conversion 100 mol%) with high selectivity towards camphene (54 mol%). To prepare activated carbons, biomass precursors (orange peels, sunflower husks, spent coffee grounds) were activated with 85% H₃PO₄ through the chemical activation. The obtained materials were characterized by such methods as sorption N₂ at - 196 °C, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and X-ray fluorescence (XRF) to determine the relationship between their textural-chemical properties and catalysts activity in isomerization process. The synthesized materials were characterized by a specific surface area in the range of 930-1764 m², total pore volume in the range of 0.551-1.02 cm³/g, and total acid-site concentrations in the range of 1.47-2.33 mmol/g. These results showed that textural parameters of the obtained activated carbons have the important role in the isomerization of α-pinene.

Activated carbons-preparation, characterization and their application in CO2 capture: A review

In this paper, we provide a comprehensive review of the latest research trends in terms of the preparation, and characteristics of activated carbons regarding CO₂ adsorption applications, with a special focus on future investigation paths. The reported current research trends are primarily closely related to the synthesis conditions (carbonization and physical or chemical activation process), to develop the microporosity and surface area, which are the most important factors affecting the effectiveness of adsorption. Furthermore, we emphasized the importance of regeneration techniques as a factor determining the actual technological and economic suitability of a given material for CO₂ capture application. Consequently, this work provides a summary and potential directions for the development of activated carbons (AC). We attempt to create a thorough theoretical foundation for activated carbons while also focusing on identifying and specific statements of the most relevant ongoing research scope that might be advantageous to progress and pursue in the coming years.

Nanoshaped Cerium Oxide with Nickel as a Non-Noble Metal Catalyst for CO2 Thermochemical Reactions

Four different nanoshapes of cerium dioxide have been prepared (polycrystals, rods, cubes, and octahedra) and have been decorated with different metals (Ru, Pd, Au, Pt, Cu, and Ni) by incipient wetness impregnation (IWI) and ball milling (BM) methods. After an initial analysis based on oxygen consumption from CO₂ pulse chemisorption, Ni-like metal, and two forms of CeO₂ cubes and rods were selected for further research. Catalysts were characterized using the Brunauer-Emmett-Teller formula (BET), X-ray spectroscopy (XRD), Raman spectroscopy, scanning electron microscopy (SEM), UV-visible spectrophotometry (UV-Vis), X-ray photoelectron spectroscopy (XPS), temperature programmed reduction (H₂-TPR) and CO₂ pulse chemisorption, and used to reduce of CO₂ into CO (CO₂ splitting). Adding metals to cerium dioxide enhanced the ability of CeO₂ to release oxygen and concomitant reactivity toward the reduction of CO₂. The effect of the metal precursor and concentration were evaluated. The highest CO₂ splitting value was achieved for 2% Ni/CeO₂-rods prepared by ball milling using Ni nitrate (412 µmol/g_cat) and the H₂ consumption (453.2 µmol/g_cat) confirms the good redox ability of this catalyst.

Carbon Dioxide Adsorption over Activated Carbons Produced from Molasses Using H2SO4, H3PO4, HCl, NaOH, and KOH as Activating Agents

Cost-effective activated carbons for CO2 adsorption were developed from molasses using H2SO4, H3PO4, HCl, NaOH, and KOH as activating agents. At the temperature of 0 °C and a pressure of 1 bar, CO2 adsorption equal to 5.18 mmol/g was achieved over activated carbon obtained by KOH activation. The excellent CO2 adsorption of M-KOH can be attributed to its high microporosity. However, activated carbon prepared using HCl showed quite high CO2 adsorption while having very low microporosity. The absence of acid species on the surface promotes CO2 adsorption over M-HCl. The pore size ranges that are important for CO2 adsorption at different temperatures were estimated. The higher the adsorption temperature, the more crucial smaller pores were. For 1 bar pressure and temperatures of 0, 10, 20, and 30 °C, the most important were pores equal and below: 0.733, 0.733, 0.679, and 0.536 nm, respectively.

Waste-based nanoarchitectonics with face masks as valuable starting material for high-performance supercapacitors

Surgical face masks waste is a source of microplastics (polymer fibres) and inorganic and organic compounds potentially hazardous for aquatic organisms during degradation in water. The monthly use of face masks in the world is about 129 billion for 7.8 billion people. Therefore, in this contribution the utilization of hazardous surgical face masks waste for fabrication of carbon-based electrode materials via KOH-activation and carbonization was investigated. The micro-mesoporous materials were obtained with specific surface areas in the range of 460 - 969 m²/g and a total pore volume of 0.311 - 0.635 cm³/g. The optimal sample showed superior electrochemical performance as an electrode material in supercapacitor in the three-electrode system, attaining 651.1F/g at 0.1 Ag^-1 and outstanding capacitance retention of 98 % after a test cycle involving 50'000 cycles. It should be emphasized that capacitance retention is one of the most crucial requirements for materials used as the electrodes in the supercapacitor devices. In this strategy, potentially contaminated face masks, common pandemic waste, is recycled into highly valuable carbon material which can serve in practical applications overcoming the global energy crisis. What is more, all microorganisms, including coronaviruses that may be on/in the masks, are completely inactivated during KOH-activation and carbonization.

Activated Carbon Modification towards Efficient Catalyst for High Value-Added Products Synthesis from Alpha-Pinene

DT0-activated carbons modified with HCl and HNO₃ acids, which were used for the first time in the catalytic process of alpha-pinene isomerization, are presented in this study. The carbon materials DT0, DT0_HCl, DT0_HNO₃, and DT0_HCl_HNO₃ were examined with the following methods: XRF, SEM, EDX, XPS, FT-IR, XRD, and N₂ adsorption at −196 °C. It was shown that DT0_HCl_HNO₃-activated carbon was the most active material in the alpha-pinene isomerization process. Detailed studies of alpha-pinene isomerization were carried out over this carbon by changing the reaction parameters such as time (5–180 min) and temperature (60–175 °C). The 100% conversion of alpha-pinene was achieved at the temperature of 160 °C and catalyst content of 5 wt% after 3 h over the DT0_HCl_HNO₃ catalyst. Camphene and limonene were the main products of the alpha-pinene isomerization reaction.

FeCl3-Modified Carbonaceous Catalysts from Orange Peel for Solvent-Free Alpha-Pinene Oxidation

The work presents the synthesis of FeCl₃-modified carbonaceous catalysts obtained from waste orange peel and their application in the oxidation of alpha-pinene in solvent-free reaction conditions. The use of waste orange peel as presented here (not described in the literature) is an effective and cheap way of managing this valuable and renewable biomass. FeCl₃-modified carbonaceous materials were obtained by a two-stage method: in the first stage, activated carbon was obtained, and in the second stage, it was modified by FeCl₃ in the presence of H₃PO₄ (three different molar ratios of these two compounds were used in the studies). The obtained FeCl_3-modified carbon materials were subjected to detailed instrumental studies using the methods FT-IR (Fourier-transform Infrared Spectroscopy), XRD (X-ray Diffraction), SEM (Scanning Electron Microscope), EDXRF (Energy Dispersive X-ray Fluorescence) and XPS (X-ray Photoelectron Spectroscopy), while the textural properties of these materials were also studied, such as the specific surface area and total pore volume. Catalytic tests with the three modified activated carbons showed that the catalyst obtained with the participation of 6 M of FeCl₃ and 3 M aqueous solutions of H₃PO₄ was the most active in the oxidation of alpha-pinene. Further tests (influence of temperature, amount of catalyst, and reaction time) with this catalyst made it possible to determine the most favorable conditions for conducting oxidation on this type of catalyst, and allowed study of the kinetics of this process. The most favorable conditions for the process were: temperature of 100 °C, catalyst content of 0.5 wt% and reaction time 120 min (very mild process conditions). The conversion of the organic raw material obtained under these conditions was 40 mol%, and the selectivity of the transformation to alpha-pinene oxide reached the value of 35 mol%. In addition to the epoxy compound, other valuable products, such as verbenone and verbenol, were formed while carrying out the process.

Conversion of fruit waste-derived biomass to highly microporous activated carbon for enhanced CO2 capture

Activated carbons were prepared from different Amazonian fruit waste-derived biomass residues from the Amazon to store CO₂ at low pressure. The samples were carbonized in under flowing N₂ flow atmosphere and activated with KOH. The carbon materials obtained were physically and structurally characterized by the analysis of N₂ isotherms for textural characterization, X-ray fluorescence (XRF), ash content, X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and applied for CO₂ adsorption. Temperature programmed desorption (TPD), the isosteric heat were also calculated. The values of the specific surface area (S_BET) ranged from 1824 to 2004 m²/g, and the total pore volume varied between 0.68 and 0.79 cm³/g. These results confirm that the obtained activated carbons are microporous materials. The highest CO₂ adsorption under the pressure of 1 bar was achieved in activated carbon derived from andiroba seeds ANKO1, the adsorption of carbon dioxide at 1 bar was being 7.18 and 4.81 mmol/g at 273 K and 298 K, respectively. As a result, the most important factor in the preparation of activated carbon for CO₂ capture is primarily rich in extremely the high amount of small micropores.

Mixed reality interactive visualization of cardiovascular anatomy in interventional lab – clinical implementation in transvascular patent ductus arteriosus closure

Aim

Three-dimensional (3D) noninvasively acquired datasets containing anatomical information about the heart are a modern option for procedural support during percutaneous cardiac interventions. We present initial experience of patent ductus arteriosus (PDA) closure with workflow integrated with innovative mixed reality display (MRD) to improve 3D perception and navigation in 3D computed tomography angiographic (CTA) datasets.

Methods

We report incorporation of intraprocedural mixed-reality display of segmented CTA (computed tomography angiography) data using a voice- and gesture controlled head-mounted display during routine percutaneous occlusions of PDA in adults. A dedicated software pathway was used for files conversion, real-time Wi-Fi streaming of 3D rendering from PC to device and manipulation of spatial data during the procedures.

Results

Pre-recorded CTA studies of aorta and ductus were manually segmented and uploaded into custom designed 3D DICOM for realtime export to MRD device. 3D holograms were successfully displayed during the procedure by commercially available head-mounted display allowing touchless control and image sharing within cath-lab. Wiring of PDA aortic orifice was assisted by 3D hologram controlled by the imaging specialist and shared by the operator. Thus, MRD using evolving versions of custom software was successfully executed with segmented data presented as a semitransparent cubic hologram positioned in a convenient part of visual field allowing real-world action and with touchless control by medical team. Operator appreciated the use of MRD hologram realistically visualizing spatial relationships as practical aid to establish anatomical relationships and facilitate entry into ductus orifice. Procedures were successfully completed using arteriovenous guidewire loop to implant vascular occluders.

Conclusions

We demonstrate the methodology and software evolution (segmentation, data fusion) allowing practical implementation of intraprocedural mixed reality display of 3D CTA data, with sterile, touchless control of holographic image shared by interventional and imaging team to support percutaneous PDA closure.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): MEDAPP

Utilization of spent dregs for the production of activated carbon for CO2 adsorption

The objective of this work was preparation of activated carbon from spent dregs for carbon dioxide adsorption. A saturated solution of KOH was used as an activating agent. Samples were carbonized in the furnace at the temperature of 550°C. Textural properties of activated carbons were obtained based on the adsorption-desorption isotherms of nitrogen at −196°C and carbon dioxide at 0°C. The specific surface areas of activated carbons were calculated by the Brunauer – Emmett – Teller equation. The volumes of micropores were obtained by density functional theory method. The highest CO2 adsorption was 9.54 mmol/cm3 at 0°C – and 8.50 mmol/cm3 at 25°C.

Adsorption of carbon dioxide on TEPA-modified TiO2/titanate composite nanorods

CO₂was successfully chemisorbed/physisorbed on a TiO₂/titanate composite nanorod functionalized with TEPA amine.

40-year experience in surgical treatment of congenital chest deformations--ethiopathogenesis, operative techniques and clinical results

PURPOSE OF THE STUDY

The aim of this study was to assess the results of surgical treatment of 58 patients with pectus excavatum and 11 with pectus carinatum and discuss the problems connected with ethiopathogenesis and operative techniques.

MATERIAL

69 chest deformations treated between 1961-2001.

METHODS

The clinical results were analyzed with 1) Kopera-Król Rtg-index, 2) Gizycka's Rtg-index of chest flattening, 3) Haller and Nakahara CT-index, 4) Heart position after operation, 5) Frequency of upper respiratory infections, 6) Appearance of postoperative scar, 7) Patient's opinion. Histopathological investigations were used to assess ethiopathogenesis of chest deformations.

RESULTS

90% permanent correction achieved in group of patients operated in the age from 12 to 17. Otherwise we noted between the patients who were operated in the age from 6 to 10-37% recurrence of deformity. Generally we had 70% excellent and good results. The opinion of patients (including cosmetics effects, psychical state and exercise tolerance) was much better-86.6%. Particularly correction of pectus carinatum gives good cosmetics effects as well as improvement of exercise tolerance.

DISCUSSION

Nuss modified correction employing a substernal stabilizing plate is an alternative for transsternal traction in the classical Ravitsch' procedure. Authors present advantages and disadvantages of both methods. The optimal age for surgical correction and inter and post operative procedure are discussed.

CONCLUSIONS

Ethipathogenesis of pectus excavatum and carinatum remains unsettled. Disturbances in endochondral ossification and growth of costal cartilage seem to be more probable cause of the deformities than diaphragm underdevelopment. Mild and severe forms of the two deformities result in circulatory-respiratory malfunctions, cosmetic defects and psychical problems. Due to possible circulatory-respiratory disorder, appropriate premedication as well as intra- and postoperative monitoring of RR, ECG, O2, CO2 are very important on the first day after the surgery. Ravistch-Garnier procedure for pectus excavatum and Chen procedure for pectus carinatum remain operations of choice. Transsternal traction can be replaced with internal stabilisation with a bar placed under the sternum what considerably reduces the time of hospitalisation but requires one more hospitalisation to remove the bar. Correction of pectus carinatum is permanent, correction of pectus excavatum turned out to be permanent in 90% cases providing that they were performed in patients aged 12-16. When patients were at the age 6-10, recurrence of the deformity occurred in 37% of cases. According to the clinical assessment, in both age groups, the proportion of very good or good scores equalled 70% and according to patient's evaluation--86.6%.

Expression of inducible nitric oxide synthase and nitrotyrosine during the evolution of experimental pulmonary tuberculosis

Nitric oxide (NO) is a relevant antimycobacterial factor in mouse macrophages. NO is a product of inducible nitric oxide synthase (iNOS). NO toxicity is greatly enhanced by reacting with superoxide to form peroxynitrite that reacts with many biological molecules. Tyrosine is one of the molecules with which NO reacts and the product is nitrotyrosine (NT). The production of peroxynitrite and the nitrosylation of proteins might play a role in bacterial killing and also in mediating host injury. In this study, we used a well-characterized mouse model of pulmonary tuberculosis to examine the local kinetics of expression and cellular distribution of iNOS and NT at the cellular and subcellular level. The histopathological study showed two phases of the disease: early and late. The early phase was characterized by mononuclear inflammation and granuloma formation. During this phase, high percentages of activated macrophages were observed that were immunostained for iNOS and NT. Immuno-electronmicroscopy showed NT immunoreactivity in lysosomes and mycobacterial wall and cytoplasm. The concentration of iNOS mRNA and NO metabolites were also elevated. The late phase was characterized by progressive pneumonia with focal necrosis and a decrease of iNOS mRNA and NO metabolites. The strongest NT immunostained areas were the necrotic tissue. Macrophages became foamy cells with scarce iNOS immunostaining but strong NT immunoreactivity. At the ultrastructural level, these cells showed NT immunolabeling in cytoskeleton, mitochondria, lysosomes and cell membrane. NT was also located in bronchial epithelial cell mitochondria, in cell membranes and cytoplasm of endothelial cells and in actin bundles within smooth muscle cells. These results suggest an important role of NO in mycobacterial killing, particularly during the early phase of the infection. They also suggest an important participation by NO in tissue damage during the late phase of the disease.

[Tibia vara infantum--long-term results]

We are presenting 23 patients with infantile tibia vara (Blount disease) treated with proximal tibial osteotomy between 1968 and 1992. Average age at the osteotomy was 6 years and 4 months. Average age at the final follow-up was 20 years and 5 months. Average length of follow-up was 14 years. Patients were evaluated clinically and radiographically. The main complaint at the final check-up was pain. Correction of the lower leg alignment did not guarantee good knee function. Horizontal orientation of the knee joint line seems to influence greatly the knee function. Patients operated on before the age of 5 were pain free with good knee form and function. In majority of those either operated on late or with recurrence of deformity early degenerative changes ensued.

Acetabular wall deficiency in primary and secondary total hip replacement

Thirty-eight cases of reconstruction of acetabular wall deficiency in primary and secondary total hip replacement were evaluated according to Merle d'Aubigne-Postel and Gruen's ratings, after a follow-up of between 1 and 8 years. 16 of them were considered very good, 11 good, 7 fair and 4 poor.The reconstructions were performed by inserting cemented Weller's or cementless Parhoffer-Mönch's or Mittelmeier's cups, depending on patients age and the nature of the lesion.In dysplastic hips the bone stock deficiency of the anterior wall and the roof were reconstructed with the use of massive autogenous cortical bone graft fixed with screws.In cases of Otto-Chrobak disease and in protrusions of Austin-Moore's prostheses, cancellous auto- or allogenous bone grafts healed correctly even after implantation of cemented sockets.The reconstruction of the acetabulum in an intrapelvic protrusion of the endoprosthesis, especially cemented ones, was always technically difficult, threatening the vessels and intrapelvic organs. This operation requires good experience as well as:-thorough radiographic diagnosis (CT, angiography external iliac artery and vein),-an appropriate surgical approach,-the use of a sufficient amount of cortico-cancellous bone auto- or allograft,-implantation of cemented or cementless cups depending on the patient's age,-restriction of weight-bearing even up to 5 months. In old patients, an alternative to full reconstruction is to remove the endoprosthesis and to leave a hanging hip (Girdlestone pseudarthrosis).

Coxa vara infantum, hip growth disturbances, etiopathogenesis, and long-term results of treatment

The literature concerning coxa vara infantum (CVI) contains only a few long-term follow-up reports of the treatment. This study was performed to define the clinical and roentgenographic features of coxa vara infantum (CVI) in children and skeletally mature patients. Special attention was given in follow-up evaluations to the growth and impairment of the hip joint (acetabulum, femoral head, and neck) before and after operative treatment in different age groups. Because in difficult cases the results of subtrochanteric osteotomy have not been satisfactory and have led to recurrences, the use of overcorrecting of the neck-shaft angle value into valgus position has been adopted. To gain further insight into etiopathogenesis of CVI, histologic investigations were carried out. These investigations revealed growth and endochondral ossification disorders. Similar changes found in the growth zone of the iliac bone seem to indicate that the ossification disturbances are multifocal. Expansion of the fibrous connective and calluslike tissues is evidence of the overload syndrome in CVI.

New refractive method for laser thermal keratoplasty with the Co:MgF2 laser

We have observed corneal curvature changes from laser thermal keratoplasty with a Co:MgF2 laser. We studied corneal curvature changes in rabbits and have identified specific treatment patterns and laser parameters that can correct myopia and astigmatism. These corneal changes, some as large as 8 diopters, have been stable for at least one year, and slitlamp examination demonstrates clear central corneas with normal appearance.

Chrono-coherent imaging for medicine

We describe a new method for imaging with visible and near visible light inside media, such as tissues, which have strong light scattering. The chrono-coherent imaging (CCI) method is demonstrated in this paper for a transmission geometry where an absorbing object is completely hidden from normal visual observation by light scattering of the media. The resultant images are most similar to X rays, with cumulative transmission showing absorption features and refractive index differences in the media. We discuss laser coherence properties, coherence measurements, the relation of CCI to light-inflight holography, holographic film properties relevant to CCI, a particular optical setup for CCI, the results of a demonstration experiment imaging an absorbing object hidden by light scattering, and an experiment to estimate the clinical applicability of CCI.

Chrono-coherent imaging for medicine

Imaging inside the body with optical wavelengths encounters problems due to light scattering of tissues and other optical distortions. A description is given of chrono-coherent imaging (CCI), a new method for imaging with visible and near-infrared light that uses coherent image formation and subpicosecond timing to remove the time-delayed scattered light. With CCI it is possible to form images in the presence of the overwhelming amount of scattered light that blocks conventional image formation. The coherent image formation process allows the use of long-duration, high-total-energy, and modest-peak-power pulses to overcome scattering losses. CCI is an extension of light-in-flight holography, which combines the properties of short-duration pulses and hologaphy for various measurements of objects and optical wavefronts.