bluuebunny/crossref_metadata_2025 huggingface dataset:
Digital analysis of trabecular pattern in jaws of patients with sickle cell anemia
Authors: White S C , Cohen J M , Mourshed F A
Published: October 2024

OBJECTIVES

To characterize how the morphological features of the cancellous bone of the maxilla and mandible differ in patients with sickle cell anemia compared with normal subjects.

METHODS

Periapical radiographs of 18 young African American patients with sickle cell anemia and 18 control African Americans were digitized at 600 d.p.i. A customized computer program measured 24 morphological features of the trabecular and marrow architecture in the anterior maxilla and mandible. The mean values for each of the features were determined for the sickle cell and control groups and compared by anatomical site.

RESULTS

Patients with sickle cell anemia have a significant increase in area of the marrow (53% compared with 47% in controls) and a less complex trabecular structure as evidenced by fewer skeletal branch points per square cm (451 compared with 584 in controls in the anterior maxilla and, 553 compared with 678 in controls in the anterior mandible). All values are significantly different (P < 0.001).

CONCLUSIONS

The data support the hypothesis that an automated image-interpretation program can distinguish patients with sickle cell anemia from normal individuals.
Fractal properties of bone
Authors: Geraets W G , van der Stelt P F
Published: October 2024

OBJECTIVE

To introduce the applications of fractal analysis of bone in medical imaging in general and dental radiographs in particular.

RESULTS

Various methods for measuring fractal dimension have been used to compare normal with osteoporotic bone with contradictory results. This disparity may be attributed to differences in the anatomical sites studied and differences in methods used to obtain the 2D images. However, differences in methods used to measure fractal dimension can also be responsible.

CONCLUSION

When fractal dimension is used to study bone it must be remembered that all stages in the analytical chain have an impact on the results. Thus, to obtain more conclusive results, studies on the fractal dimension of bone should be carefully designed and individual methods thoroughly evaluated.
Computed tomography of emphysema following tooth extraction
Authors: Wakoh M , Saitou C , Kitagawa H , Suga K , Ushioda T , Kuroyanagi K
Published: October 2024

Subcutaneous and tissue space emphysema following surgical extraction of mandibular third molars is a rare and serious complication of dental surgery. Recognition of mediastinal emphysema following surgical extraction is difficult because there are no absolute clinical symptoms and signs. We present two cases of emphysema following extraction of a lower third molar and discuss the contribution of CT to the early recognition of the presence and spatial migration of air and to clinical management.
Recent developments in understanding temporomandibular joint disorders. Part 2: Changes in the retrodiscal tissue
Authors: Sano T
Published: October 2024

The purpose of the second in the series of three review articles is to discuss the significance of changes in the retrodiscal tissue on MRI of the painful TMJ in patients with TMD. Decreased T1W or proton signal in the retrodiscal tissue is related neither to TMJ pain nor histologically clarified. However the increased MR signal, suggestive of higher vascularity, may reflect TMJ pain.
Comparison of the panoramic radiographic and CT features of post-Caldwell-Luc maxillary sinuses
Authors: Ohba T , Morimoto Y , Nagata Y , Tanaka T , Kito S
Published: October 2024

OBJECTIVE

To clarify the panoramic radiographic features of the post-Caldwell-Luc maxillary sinus.

METHODS

The panoramic radiographs were compared with the axial CT scans of 48 symptomatic post-Caldwell-Luc maxillary sinuses which had been operated on more than 5 years previously.

RESULTS

The two characteristic features of the post-Caldwell-Luc maxillary sinus on panoramic radiographs were a right-angled triangular shape, due to absence of the floor of the maxillary sinus and radiopacity of the posterior wall and zygomatic bone, and an ill-defied panoramic innominate line. This shape was related to the finding of a contracted sinus with a radiolucent lumen on the CT scans. There was also close relationship between the ill-defined panoramic innominate line and thickened posterior wall on the CT scans.

CONCLUSION

The characteristic features of the post-Caldwell-Luc maxillary sinus on panoramic radiographs were a right-angled triangular shape and an ill-defined panoramic innominate line. These features were related to a contracted sinus and a thickened posterior wall on the CT scans.
Experimental induction of rheumatoid arthritis in temporomandibular joint of the guinea pig: a clinical and radiographic study
Authors: Al-Mobireek A F , Darwazeh A M , Hassanin M B
Published: October 2024

OBJECTIVE

To correlate the clinical and radiographic changes at different stages of experimentally-induced rheumatoid arthritis (RA) of the TMJ.

METHODS

Forty eight adult male guinea pigs, aged 4-6 months, were divided into two groups. Arthritis was induced in the experimental animals by intraperitoneal injection of heat-inactivated group A Streptococcus pyogenes. Four animals from each group were sacrificed and examined clinically and radiographically at intervals of 48 h and 1, 2, 4, 6 and 8 weeks.

RESULTS

The main clinical findings were stiffness, crepitation and reduction in mouth opening. Radiographically, the main features were condylar erosion, flattening and sclerosis subcortical cyst formation.

CONCLUSION

RA passes through stages that can be correlated clinically and radiographically. Both the clinical and radiographic manifestations in this experimental model are comparable with those previously reported in the small joints of humans.
Magnetic resonance imaging of temporomandibular disorders: classification, prevalence and interpretation of disc displacement and deformation
Authors: Milano V , Desiate A , Bellino R , Garofalo T
Published: October 2024

AIM

To analyse the prevalence of disc displacements and deformations from MRI of symptomatic temporomandibular disorders (TMD).

METHODS

The study was conducted retrospectively on 192 joints of 98 patients (67 females, 31 males, mean age 29 years), who had undergone bilateral MRI (except for four who had unilateral) in the sagittal (both open and closed mouth) and coronal (closed mouth only) planes. These displacements were subdivided into static (complete anterior and posterior, partial anterolateral and anteromedial, sideways lateral and medial, anterolateral and anteromedial rotational) and dynamic (with reduction, without reduction, with incomplete reduction; non-determinable). Disc deformations were subdivided into: enlargement of the posterior band, reversed biconcave shape, biplanar (flattened) and biconvex shape.

RESULTS

Eighty per cent of patients had bilateral displacement, 15% unilateral and 5% a normally positioned disc. Complete anterior displacement was the commonest and sideways the rarest. Reduction was present in 58% of disc displacements, no reduction in 26%, incomplete reduction in 4%, while in the remaining 12%, it could not be determined. Rotational displacement was the most likely to feature reduction and sideways the least. Temporomandibular joints with no reduction were closely correlated with bone lesions. The most frequent deformation was biplanar and the rarest enlargement of the posterior band.

CONCLUSIONS

There was a high prevalence of displacements and deformations. While they do not appear to be significant in inducing pain, they can predispose to the onset of osteoarthrosis.
Radiographic digital image enhancement. Part II: transform domain techniques
Authors: Analoui M
Published: October 2024

Digital image enhancement techniques can have a significant impact on the diagnostic quality of a radiographic image. Selection of an image enhancement technique is a function of image content and its attributes of interest. The diagnostic value of a radiographic image is commonly reduced by its intrinsic limitations as well as interference from unwanted signals. In this second article on radiographic image enhancement the Fourier transform, the most commonly used transformation method, is used to examine examples of methods for image enhancement, with particular emphasis on the removal or reduction of noise.
The effects of different image file formats and image-analysis software programs on dental radiometric digital evaluations
Authors: Gürdal P , Hildebolt C F , Akdeniz B G
Published: October 2024

OBJECTIVES

To determine if variations in radiodensity data are introduced by lossy Joint Photographic Experts Group (JPEG) compression and/or the use of three software programs.

METHODS

An occlusal film with an aluminium step wedge was exposed, processed and digitized under standard conditions. Before the image was saved, the coordinates and the gray-scale value for each pixel in a 20 x 20 pixel area near the middle of the thickest step were recorded. These pixel coordinates and gray-scale values served as Truth 1. In addition, a digital simulated-radiographic image with assigned gray-scale values for each pixel was created and served as Truth 2. The digital data for the scanned radiograph and the simulated radiograph were saved as Tagged Image File Format (TIFF) and lossy JPEG files. Each file was opened with three software programs and the gray-scale values of homologous pixels were recorded. For these pixels in each image type, the mean gray-scale values and standard deviations were calculated. The pixel gray-scale values for each homologous pixel were also individually compared.

RESULTS

When the TIFF images were opened with the three software programs, one program resulted in gray-scale values that were not concordant with truth. All JPEG images resulted in gray-scale values that were not concordant with truth.

CONCLUSIONS

One software program added a column of 0s to data files. Lossy JPEG compression introduced potentially deleterious variations to radiodensity data, and at least two of the software programs performed JPEG image decompression differently.
Resorption of the lateral pole of the mandibular condyle in temporomandibular disc displacement
Authors: Kurita H , Ohtsuka A , Kobayashi H , Kurashina K
Published: October 2024

OBJECTIVES

To assess the possible relationship between resorption of the superolateral pole of the mandible condyle (RSLC) and TMJ disk displacement.

METHODS

Two hundred and seventeen TMJs in 138 patients were studied. Displacement of the disc, degree of displacement and disc configuration were assessed using MRI. RSLC was assessed from a transorbital radiograph.

RESULTS

Seventy-two joints (37%) were considered to have RSLC. A significantly higher prevalence of RSLC was found in joints with disc displacement (goodness test of fit for chi-square, P<0.05). A significantly higher prevalence of RSLC was found in joints with advanced disc displacement and advanced disk deformation (Mann-Whitney U-test, P<0.01).

CONCLUSIONS

RSLC appears more likely to occur in joints with advanced disc displacement.
Detection of simulated periodontal bone gain by digital subtraction radiography with tuned-aperture computed tomography. The effect of angular disparity
Authors: Chai-U-Dom O , Ludlow J B , Tyndall D A , Webber R L
Published: October 2024

OBJECTIVES

To investigate the influence of angular disparity on observer detection of simulated bone gain in digital subtraction radiography using tuned-aperture computed tomography (TACT).

MATERIALS AND METHODS

Simulated periodontal defects were created in interproximal and buccal or lingual (tooth-obscured) areas of the premolar and molar regions of a dry human skull. Radiographs were obtained before and after known weights of amorphous bone were added to the defects to simulate bone gain. The skull was positioned in a multidirectional tomographic unit to achieve reproducibility. A series of nine basis images were acquired with a CMOS intra-oral receptor and repeated using angular disparities of 10 degrees, 20 degrees, and 30 degrees. Stacks of TACT slices generated from the basis images were paired for image-registration, histogram-equalization and subtraction using TACT Workbench. Eight calibrated observers randomly assessed the presence or absence of bone gain using a 5-point confidence scale. ROC curves were generated and A(z) values were analysed using ANOVA.

RESULTS

There were significant differences in the performance of the observers (P=0.034), defect location (P=0.005), amount of bone gain (P<0.001), angular disparity (P=0.003) and angular disparity x defect location interaction (P=0.019). Mean A(z) values in detecting bone gain were 0.90, 0.85, 0.79 for angular disparities of 10 degrees, 20 degrees, and 30 degrees respectively.

CONCLUSIONS

Smaller angular disparity provided better detection of bone gain with TACT-subtraction using nine basis-projections. This effect of angular disparity was especially evident with tooth-obscured defects.
Systematic review in diagnostic radiology.
Authors: MacDonald-Jankowski D S , Dozier M F
Published: October 2024

Systematic review (SR) already makes a major contribution to evidence-based healthcare by making the review process transparent and by reducing bias. SR has been successfully applied to observational studies. Radiologists have already begun to make an impact in dentistry by using SR as a decision-making tool. Central to SR is establishment of a research question, selection criteria, a search plan, a literature search, an appraisal of the identified literature by the selection criteria; an analysis and a formulation of recommendations. With regard to the literature search, electronic databases (Medline, Embase, Science Citation Index, Lilacs), controlled subject headings, exploding and free-text searching, handsearching and the gray literature are discussed.
Ectopic parotid gland as an unusual cause of cheek swelling
Authors: Boyd D , Bates C , Macleod R I
Published: October 2024

There are numerous causes for chronic cheek swelling, including masseteric hypertrophy, lymphadenopathy, diffuse inflammatory changes and neoplasia. We report an unusual case where the swelling was the result of ectopic parotid tissue.
Volumetry of simulated bone grafts in the edentulous maxilla by computed tomography: an experimental study
Authors: Johansson B , Grepe A , Wannfors K , Aberg P , Hirsch J M
Published: October 2024

OBJECTIVE

To determine the precision of CT for calculating the volume of bone grafts to the maxilla.

METHODS

Plaster of Paris was used to simulate bone as onlay and inlay grafts to the maxillary alveolus and sinus in a dry skull. Two mm thick axial CT scans were obtained. The area of the graft on each slice was measured and volumes calculated according to the formula V(graft)=Sigma of areas x the thickness of each section. Scans were repeated with the skull at approximately +5 degrees and -5 degrees to the horizontal plane and the calculations repeated. The real volume was calculated by the displaced water technique. Precision was estimated as reliability coefficient.

RESULTS

The reliability coefficients for the right and left inlay and the onlay grafts were 0.97, 0.6 and 0.96 respectively.

CONCLUSION

Calculations of the volume of both inlay and onlay grafts to the maxilla from axial CT is precise.
A clinical study of changes in the volume of bone grafts in the atrophic maxilla
Authors: Johansson B , Grepe A , Wannfors K , Hirsch J M
Published: October 2024

OBJECTIVES

To evaluate the volumetric changes in bone grafts to the severely atrophic edentulous maxilla over 6 months.

METHODS

Ten edentulous patients received autogenous bone as buccal onlay grafts to the maxilla and bilaterally particulate bone grafts to the maxillary sinus. Two mm contiguous axial CT scans were obtained 1 to 2 weeks and 6 to 7 months postoperatively. The area of each graft was measured and the volume calculated according to the formula V(graft)=Sigma of areas x the thickness of each section.

RESULTS

The volume of the inlay and onlay grafts was reduced by an average of 49.5 and 47% respectively of the initial volume. The coefficient of variation was greater in the onlay group (0.79) compared with the inlay group (0.38).

CONCLUSIONS

The volumetric changes in buccal onlay and sinus inlay grafts after 6 months of healing seem similar although there was a wide range in both groups.
Evaluation of pulse sequences used for magnetic resonance sialography
Authors: Sakamoto M , Sasano T , Higano S , Takahashi S , Nagasaka T , Yanagawa I , Hosogai Y , Tamura H , Iikubo M , Shoji N
Published: October 2024

OBJECTIVES

To determine the most appropriate sequences for the visualization of small parotid ducts in MR sialography.

METHODS

MR images of a phantom consisting of distilled water in polyethylene tubes were obtained with turbo-spin echo (TSE), single-shot turbo-spin echo (SSTSE), half-fourier acquisition, single-shot turbo-spin echo (HASTE) and turbo gradient-spin echo (TGSE) pulse sequences and compared visually and quantitatively. MR sialograms obtained from healthy volunteers and patients with Sjögren's syndrome (SS) were obtained using the same four sequences.

RESULTS

In the phantom, TSE images were best and the contrast-noise ratio (CNR) highest. In the volunteers, the main ducts were especially clearly visualized with TSE and in SSTSE; however, the majority of secondary and/or tertiary parotid ducts were not depicted by any of the sequences used. In SS patients, images of small main ducts and small pseudocysts were clearer using TSE. However, TSE could not depict the narrow main ducts or peripheral ducts or very small pseudocysts.

CONCLUSIONS

TSE is considered the most suitable MR sequence for assessing small parotid gland ducts. However, further improvement is needed since it does not always visualize them sufficiently.
Imaging of biodegradable osteosynthesis materials by ultrasound
Authors: Heidemann W , Gerlach K L
Published: October 2024

OBJECTIVE

Biodegradable osteosynthesis materials are not radio-opaque and therefore not visible on conventional X-rays. The aim of this study is to investigate the use of ultrasound for imaging biodegradable materials to detect and monitor the degradation process.

METHODS

Forty-six patients had two different polylactide osteosynthesis fracture plate materials used for the fixation of midfacial fractures. A 7.5 MHz ultrasound transducer with a 4.2 x 0.9 cm footprint was used by two examiners at approximately 4-month intervals over 36 months to monitor changes of the latero-orbital and infra-orbital rims.

RESULTS

Intrinsically amorphous 50 : 50 poly(D,L)lactide reached the maximum of thickness (about 300% of the initial thickness) between 14 and 18 months post-implantation and was totally resorbed in clinical and ultrasound examinations 30 months post-implantation. In 85 : 15 poly(L,D)lactide plates, the maximum of thickness (about 300% of the initial thickness) was reached between 22 and 26 months post-implantation and resorption was still in progress 36 months post-implantation.

CONCLUSION

Ultrasound examinations are suitable for detecting and monitoring the degradation process of biodegradable osteosynthesis plates in the peri-orbital region.
Influence of room lighting on grey-scale perception with a CRT-and a TFT monitor display
Authors: Haak R , Wicht M J , Hellmich M , Nowak G , Noack M J
Published: October 2024

OBJECTIVES

To determine the influence of ambient lighting on grey-scale perception using a cathode-ray tube (CRT) and a thin film transistor (TFT) computer display.

METHODS

A cathode ray tube (Nokia XS 446) and a liquid crystal display (Panasonic LC 50S) were used at reduced room lighting (70 lux) and under conditions recommended for a dental operatory (1000 lux). Twenty-seven observers examined twice a modified SMPTE test pattern [0 to 255; 255 to 0] grey-scale values. The corresponding contrast differences were allocated to four ranges of grey levels (I: 0-63; II: 64-127; III: 128-191; IV: 192-255). The influences of monitor type, grey-scale range and illumination were evaluated by means of repeated measures analysis of variance.

RESULTS

Detection of differences in monochromatic intensity was significantly earlier with reduced lighting (P<0.0001). When full ambient lighting was used, the TFT display was superior compared to the CRT monitor in ranges II and III (P<0.0001), whereas no differences could be detected for grey intensities between 0 and 63 (P=0.71) and between 192 and 255 (P=0.36).

CONCLUSIONS

Background lighting hampers grey-scale perception on computer displays. In this study of one TFT and one CRT monitor, the TFT in full ambient lighting was associated with earlier detection of grey scale differences than CRT.
Survey of radiography and radiation protection in general dental practice in Uganda
Authors: Mutyabule T K , Whaites E J
Published: October 2024

OBJECTIVES

To carry out the first survey in Uganda of all dentists and all public health dental officers (PHDO) to assess the status of dental radiography and radiation protection.

METHODS

All 74 dentists and 76 PHDOs in Uganda were sent a postal questionnaire including 33 questions relating to various demographic details, radiographic equipment and radiographic techniques, including processing and radiation protection. A second questionnaire was sent to non-respondents after 3 months.

RESULTS

Eighty-two per cent of dentists responded and 83% of PHDOs. Seventy per cent of the dentists and 100% of the PHDOs were trained in Uganda. Seventy-five per cent of the dentists and 30% of the PHDOs had access to one of the approximately 30 X-ray machines in the country. The majority of the equipment did not comply with current recommendations in Europe. Fifty-one per cent of dentists used machines with mechanical timers, 28% used machines with no visual warning signal and 17% used equipment with no audible warning signal. Most of the equipment was over 30 years old and only 15% of dentists knew when the equipment was last serviced. The most relevant finding of the surveys was the level of 'don't know' responses to many questions from both groups.

CONCLUSIONS

The lack of knowledge regarding dental radiography and radiation protection plus the condition of most equipment in Uganda is a matter of concern. Standards of care are considerably lower than in developed countries requiring improved undergraduate training, provision of postgraduate courses and Ugandan governmental or international financial assistance.
Accuracy of caries detection with four storage phosphor systems and E-speed radiographs
Authors: Hintze H , Wenzel A , Frydenberg M
Published: October 2024

OBJECTIVE

To evaluate the accuracy of caries detection using four intra-oral storage phosphor plate systems exposed with two different exposure times and one film system.

METHODS

Under in vitro and standardised conditions 365 approximal and 159 occlusal surfaces were radiographed using four storage phosphor plate systems: DenOptix, Cd-dent, Digora (blue and white plates) and one film system: Ektaspeed Plus. The plates were exposed twice with 10% and 25% of the time needed for the film. Four observers recorded approximal enamel/dentine and occlusal dentine caries using a five-point confidence scale. Caries presence was validated histologically and diagnostic accuracy of the systems by using ROC curve areas (Az).

RESULTS

The shorter exposure time for approximal caries, Digora(white)(Az=0.68) and Ekta Plus (Az=0.69) were significantly more accurate than the other systems (Az=0.64-0.65). For occlusal caries using the same exposure time, no significant difference was found between the digital systems (Az=0.76-0.77), which all showed to be significantly less accurate than Ekta Plus (Az=0.81). Using the longer exposure time for approximal caries, no significant difference was found between DenOptix (Az=0.68), Digora(blue) (Az=0.69), Digora(white) (Az=0.69) and Ekta Plus (Az=0.69) which were all significantly more accurate than Cd-dent (Az=0.65). For occlusal caries using the same exposure time, Digora(blue) (Az=0.81) was the most significantly accurate of the digital systems. When approximal caries was the diagnostic task, the longer exposure time resulted in significantly higher accuracy with the DenOptix and Digora(blue) systems but not with the Cd-dent and Digora(white) systems. For occlusal caries, the longer exposure time resulted in a significant improvement only with the Digora(blue) system.

CONCLUSION

For approximal caries using the longer exposure time, no significant difference in diagnostic accuracy was found between DenOptix, Digora(blue), Digora(white) and Ekta Plus which were all significantly more accurate than the Cd-dent. For occlusal caries using the longer exposure time, Digora(blue) was found to be the most accurate of the digital systems. The exposure time had an influence on the diagnostic accuracy with the DenOptix and Digora(blue) systems for approximal and with the Digora(blue) system for occlusal caries detection.
Lymphoepithelial lesion of the parotid gland
Authors: Goto T K , Shimizu M , Kobayashi I , Chikui T , Kanda S , Toshitani K , Shiratsuchi Y , Yoshida K
Published: October 2024

We describe a case of lymphoepithelial lesion of the parotid gland, also known as salivary lymphoepithelial lesion. Lymphoepithelial lesions are usually seen in conjunction with autoimmune disease of the salivary glands and these lesions do not always remain benign. Our case consisted of two masses that had different imaging features. Moreover, we could investigate the changes of the size and internal architecture on imaging due to the postponement of surgical intervention on the masses. At review 6 months later, the size of the masses had increased. The aims of this paper were to: (1) investigate the contribution of gray-scale sonography, power Doppler sonography, magnetic resonance imaging, and computed tomography to the diagnosis; and (2) consider the appropriate imaging modality to follow-up this case to monitor for recurrence or malignant transformation.
The accuracy and reliability of radiographic methods for the assessment of marginal bone level around oral implants
Authors: De Smet E , Jacobs R , Gijbels F , Naert I
Published: October 2024

OBJECTIVES

To determine the accuracy and reliability of radiographic methods for assessment of the marginal bone level around oral implants in human cadavers.

METHODS

In three human cadavers two implants were placed according to the Instruction Manual for the Brånemark System. One implant was installed in the canine and one in the premolar region of the left mandible. For each implant, conventional and digital intra-oral paralleling radiography were performed. Digital images were printed with a Kodak 1200 Distributed Medical Imaging printer on blue transparent film, glossy and plain paper. Furthermore, digital scanographic, panoramic and tomographic images were taken with the Cranex Tome multimodal X-ray unit and printed on Agfa Drystar TM 1 B transparent films. All images were evaluated by five dental specialists. Data were statistically compared with real measurements of the marginal bone level on the human cadavers, performed by the same group of observers. Intra- and inter-observer variability were determined.

RESULTS

Digital intra-oral images on glossy paper showed the smallest absolute difference between real and measured bone level, followed by digital intra-oral images on film and on plain paper, conventional intra-oral images on analogue film, panoramic, scanographic and tomographic images on film. The difference between real and radiographic measurements was not statistically significant (P>0.05) for all radiographic techniques. Intra- and inter-observer reproducibility was high for all techniques.

CONCLUSIONS

The selected imaging techniques showed an acceptable accuracy for peri-implant bone level measurements with an overall error of less than 0.5 mm. Intra-oral images showed the smallest absolute differences.
Introduction
Authors: Tolomelli A. , Ferrazzano L. , Cabri W.
Published: October 2024

The increasing number of new therapeutic oligopeptides and oligonucleotides, commonly referred to as TIDES, approved each year has led to consistent and rapid growth of the market size and the need to produce large volumes of these active pharmaceutical ingredients. In addition, in TIDES chemistry, the experimental design has to be tailored for each specific molecule and the most suitable technology often has to be selected from among a number of effective approaches. The design and development of sustainable processes are therefore necessary to guarantee not only optimal purity and yield, but also effective management of solvents, reagents, energy and waste. This introductory chapter outlines the purpose of this book, namely to serve as a valuable reference for TIDES synthesis and sustainability, in which specific topics are highlighted that are discussed in the following chapters.
Impact of Impurities on the Quality and Safety of Oligonucleotides as Drug Substances
Authors: Kaufmann J. , Rupp T. M.
Published: October 2024

The process of solid-phase oligonucleotide synthesis (SPOS) is well established and has been used in recent decades for the chemical synthesis of RNA therapeutics. With the growing understanding of RNA therapeutics, their overall structural design evolved to enhance efficacy, stability, or delivery by the introduction of various modifications. This had a direct impact on the impurities generated and their control. In parallel, the understanding of chemistry, manufacturing, and controls (CMC) was greatly enhanced by the advances in analytical techniques. Understanding of the manufacturing process and defined analytical checkpoints allow impurities to be traced back to the originating process step. This knowledge in turn can be used during process development to develop tight control strategies that enhance product quality. With the current speed of approvals of RNA therapeutics and the rapidly growing pipeline, regulations and guidelines are needed to ensure drug safety. The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) Guidelines ICH Q3A Impurities in New Drug Substances, Q3B Impurities in New Drug Products, and Q6A Specifications: New Chemical Drug Substances and Products exclude oligonucleotides as the guidance provided therein for small-molecule registration cannot be directly applied. In 2017, the Oligonucleotide Safety Working Group (OSWG) took a step forward to close this gap by publishing a White Paper on impurities in oligonucleotide drug substances and drug products. This chapter discusses regulations, suggestions, and opinions on the control of impurities formed during the manufacture of synthetic RNA therapeutics and related CMC strategies.
Retraction: Enhancement of the photocatalytic activity of rhenium(i) complexes by encapsulation in light-harvesting soft nanotubes
Authors: Kameta Naohiro , Aoyagi Masaru , Asakawa Masumi
Published: October 2024

Retraction of ‘Enhancement of the photocatalytic activity of rhenium(I) complexes by encapsulation in light-harvesting soft nanotubes’ by Naohiro Kameta et al., Chem. Commun., 2017, 53, 10116–10119, https://doi.org/10.1039/C7CC05337A.
Mechanistic insights into the oxidative coupling of methane over a Li/MgO catalyst: an experimental and microkinetic modeling study
Authors: Xiong Zaili , Guo Jijun , Deng Yuwen , Zeng Meirong , Wang Zhandong , Zhou Zhongyue , Yuan Wenhao , Qi Fei
Published: October 2024

This study investigates the oxidative coupling of methane (OCM) using a Li/MgO catalyst in a packed bed reactor.
Challenges for error-correction coding in DNA data storage: photolithographic synthesis and DNA decay
Authors: Gimpel Andreas L. , Stark Wendelin J. , Heckel Reinhard , Grass Robert N.
Published: October 2024

Photolithographic synthesis and decay – underexplored challenges to DNA data storage – are characterized in this study, uncovering avenues for workflow and codec optimizations. To aid the latter, scenarios to benchmark codecs are presented.
Triboelectric nanogenerators with groove textures and carbon fillers for self-powered cathodic protection
Authors: Yang Weixu , Ma Zepeng , Yang Suqing , Hu Yanqiang , Zhang Lu
Published: October 2024

Contact-separation mode triboelectric nanogenerators (CS-TENG) with groove textures and carbon fillers for self-powered cathodic protection.
Synthesis of biobased polyacetals: a review
Authors: Renner Anna C. , Thorat Sagar S. , Sibi Mukund P.
Published: October 2024

Biobased polyacetals, as sustainable materials, are not only reprocessable and recyclable but also exhibit a range of mechanical properties. These attributes significantly broaden their potential applications across various industries.
Long short‐term memory‐based forecasting of uncertain parameters in an islanded hybrid microgrid and its energy management using improved grey wolf optimization algorithm
Authors: Krishna Raji , S Hemamalini
Published: October 2024

An islanded hybrid AC‐DC microgrid interconnects renewable energy sources, distributed generators, and energy storage, primarily for remote areas without grid access. Its reliability depends on variable renewable output and load demand, while an energy management system optimizes power scheduling and reduces costs. In the first phase of this paper, uncertainty parameters like day‐ahead power from renewable energy sources (RES) and load demand (LD) are forecasted using the long short‐term memory (LSTM) deep learning algorithm. The LSTM outperforms the artificial neural network (ANN) model in terms of mean square error (MSE) and prediction accuracy (R2) for both training and testing datasets. In the second phase, the forecasted RES power and LD are used for optimal distributed generator (DG) scheduling using the improved grey wolf optimization (IGWO) algorithm. The objective of energy management in an islanded hybrid microgrid (HMG) is to minimize daily operating costs by considering load demand and the bidding costs of energy sources and storage devices. Two operational scenarios are evaluated to minimize the operating costs and optimize battery life. The proposed method, validated with IEEE standard test systems, is compared against several metaheuristic techniques. Results demonstrate that the improved grey wolf optimization (IGWO) algorithm is more effective at reducing costs and provides faster optimal solutions.
Power quality improvement of grid‐connected solar power plant systems using a novel fractional order proportional integral derivative controller technique
Authors: Manoharan Hariprabhu , Karuppannan Sundararaju , Chandrasekaran Kumar , Barua Sourav
Published: October 2024

Recently, there has been a push to integrate renewable energy system (RES) into grid‐connected load system in enhancing reliability and reducing losses. However, integrating these systems introduces power quality (PQ) issues, especially with non‐linear, critical, and imbalanced loads. Addressing this, a hybrid mantis search‐reptile search algorithm (HMS‐RSA) combined with a unified power quality conditioner (UPQC) to mitigate PQ problems related to current and voltages in RES systems. In other words, the UPQC, enhanced by fractional order proportional integral derivative controller parameters tuned using the proposed HMS‐RSA assists in enhancing the power quality. The approach has been validated by connecting a non‐linear load to the system, which typically creates PQ issues. The proposed method is implemented in MATLAB/Simulink and their performance is analysed in three scenarios, such as sag, swell, and disturbance, and the total harmonic distortion is evaluated to quantify improvements in PQ. Finally, the proposed method is compared with existing approaches, such as ant colony optimization (ACO), artificial bee colony optimization (ABC), and bacterial foraging optimization (BFO). The method also outperforms ACO, ABC, and BFO in terms of convergence speed and effectiveness in mitigating PQ issues.
A machine learning approach to estimate mid-infrared fluxes from WISE data
Authors: Fonseca-Bonilla Nuria , Cerdán Luis , Noriega-Crespo Alberto , Moro-Martín Amaya
Published: October 2024

Context. While the Wide-field Infrared Survey Explorer (WISE) is the largest, best quality infrared all-sky survey to date, a smaller coverage mission, Spitzer, was designed to have better sensitivity and spatial resolution at similar wavelengths. Confusion and contamination in WISE data result in discrepancies between them.

Aims. We aim to present a novel approach to work with WISE measurements with the goal of maintaining both its high coverage and vast amount of data while, at the same time, taking full advantage of the higher sensitivity and spatial resolution of Spitzer.

Methods. We have applied machine learning (ML) techniques to a complete WISE data sample of open cluster members, using a training set of paired data from high-quality Spitzer Enhanced Imaging Products (SEIP), MIPS and IRAC, and allWISE catalogs, W1 (3.4 μm) to W4 (22 μm) bands. We have tested several ML regression models with the aim of predicting mid-infrared fluxes at MIPS1 (24 μm) and IRAC4 (8 μm) bands from WISE variables (fluxes and quality flags). In addition, to improve the prediction quality, we have implemented feature selection techniques to remove irrelevant WISE variables.

Results. We have notably enhanced WISE detection capabilities, mostly for the targets with the lowest magnitudes, which previously showed the largest discrepancies with Spitzer. In our particular case, extremely randomized trees was found to be the best algorithm to predict mid-infrared fluxes from WISE variables, attaining coefficients of determination R2 ∼ 0.94 and R2 ∼ 0.98 for 24 μm (MIPS1) and 8 μm (IRAC4), respectively. We have tested our results in members of IC 348 and compared their observed fluxes with the predicted ones in their spectral energy distributions. We show discrepancies in the measurements of Spitzer and WISE and demonstrate the good concordance of our predicted mid-infared fluxes with the real ones.

Conclusions. Machine learning is a fast and powerful tool that can be used to find hidden relationships between datasets, as the ones we have shown to exist between WISE and Spitzer fluxes. We believe this approach could be employed for other samples from the allWISE catalog with SEIP positional counterparts, and in other astrophysical studies in which analogous discrepancies might arise when using datasets from different instruments.
Roman stone masonry walls: The application of Ground Penetrating Radar to ancient structures
Authors: Parnow Saeed , Ciampoli Luca Bianchini , Uzor Stephen , Cox Phil , Loreti Ersilia Maria , Ten Alessandra , Benedetto Andrea , Tosti Fabio
Published: October 2024

An investigation on estimating Roman stone masonry wall thickness using non-invasive Ground Penetrating Radar (GPR) and Light Detection and Ranging (LiDAR) technology is presented in this paper. Historical building conservation and structural evaluation require correct wall thickness measurements. The methodology encapsulates data collection, signal processing, and interpretation techniques, including the use of local frequency attributes tailored for historical masonry structures. The main perimeter wall at the Circus of Maxentius, Rome, Italy, is used as the case study. The results indicate that GPR is capable of accurately estimating the thickness of Roman stone masonry walls. By conducting a comparative analysis against a wall section with a known thickness, it has been demonstrated that GPR is a dependable and precise method for conducting archaeological and architectural research. This study highlights the potential of using GPR attributes as a non-destructive investigative methodology in the field of heritage preservation. Future research includes extracting and improving further attributes and applying this approach to other historical structures.
Enhancing the Performance and Sustainability of Cementitious Composites through the Optimized Use of Steel Slag: Particle Size and Activation Techniques
Authors: Cheng Jason Ting Jing , Wei Lee Foo , Kun Yew Ming , Jie Chin Ren , Chieh Yip Chun
Published: October 2024

The utilization of industrial by-products such as steel slag in cementitious materials not only mitigates environmental impact but also enhances material properties. This study investigates the dual influence of steel slag particle size on the compressive strength and carbonation efficiency of cementitious composites. Through a systematic experimental approach, steel slag particles were incorporated into cement at varying sizes, and the resulting composites were subjected to mechanical and carbonation tests. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) are conducted in this paper. The findings reveal a positive correlation between increased particle size and compressive strength, attributed to the improved interfacial transition zone and packing density. Conversely, smaller particle sizes exhibited enhanced carbonation efficiency, likely due to the increased surface area facilitating the carbonation reaction. The presence of higher silica and calcium content in finer particles was confirmed by EDX, which contributed to the accelerated carbonation process. This study underscores the importance of particle size optimization in designing sustainable cementitious materials with balanced mechanical performance and carbon sequestration potential. The insights gained from the advanced analytical techniques offer a comprehensive understanding of the mechanisms at play, paving the way for the strategic use of steel slag in eco-friendly construction practices.
Pauli energy contribution to nucleus-nucleus interaction
Authors: Umar A.S. , Godbey K. , Simenel C.
Published: October 2024

The investigation delves into understanding how the Pauli exclusion principle influences the bare potential between atomic nuclei through the application of advanced theoretical methodologies. Specifically, the application of the novel Frozen-Hartree-Fock (DCFHF) technique is employed. The resulting potentials demonstrate a noticeable repulsion at short distances, attributed to the eﬀects of the Pauli exclusion principle. To account for dynamic phenomena, such as nucleon transfer processes, the density-constrained time-dependent Hartree-Fock (DC-TDHF) method is utilized. This approach integrates isovector contributions into the potential, shedding light on their influence on fusion reactions. Notably, the inclusion of isovector eﬀects leads to a reduction or enhancement in the inner part of the potential, suggesting a nuanced role of transfer in the fusion process.
Superheavy nuclei and other exotics – opportunities at SPIRAL2 and S3
Authors: Ackermann Dieter
Published: October 2024

The structure of very heavy and superheavy nuclei (SHN) as well as the location of the next proton and neutron shell closures beyond 208Pb is still one of the most intriguing topics in modern nuclear physics [1]. Worldwide competitive, high beam intensities provided by the accelerator facility SPIRAL2 at GANIL which started operation recently, will cover in future all ions up to uranium thanks to the new injector project NEWGAIN. Combined with the separator-spectrometer installation S3 [3], it will provide the instrumental prerequisites for an ambitious science program. Apart from SHN/SHE research, the envisaged physics case at S3 covers, among other, the structure of N=Z nuclei, low energy physics (fundamental properties of the atomic nucleus etc.), interdisciplinary research, atomic physics and reaction studies (fission, deep inelastic reactions etc.). The state of the art of the field is discussed in this paper with an emphasis on the role of the odd particle(s) in odd-even, even-odd and odd-odd nuclei and the consequences for nuclear structure features like K-isomers, trends of single-particle energies as a function of deformation, and the competition of spontaneous fission (SF) and α decay. As an alternative approach to produce heavy and in particular more neutron-rich nuclear species multi-nucleon transfer reactions are briefly discussed as well.
Nucleon-nucleon correlations probed in sub-barrier transfer reactions and the nuclear Josephson effect
Authors: Corradi L.
Published: October 2024

In recent years a series of near- and sub-barrier transfer experiments have been carried out at LNL, with reaction products detected in inverse kinematics and at forward angles with the large solid angle magnetic spectrometer PRISMA. Nucleon-nucleon correlation properties have been studied by measuring transfer cross sections far below the Coulomb barrier, making excitation functions down to very low energies and corresponding to very large distances of closest approach where the nuclear absorption is small. Such kind of studies are of general interest since one probes the tails of the density distributions. One subtle case is the possible manifestation of a nuclear Josephson effect. Predictions have been made of a specific gamma strength function associated with the dipole oscillations generated by the, mainly successive, two neutron transfer process. The coupling of PRISMA to the AGATA gamma array, recently installed at LNL, offered a unique opportunity to study such an effect. In a very recent experiment we directly tested for the first time the possible manifestation of Cooper pair oscillations, observed to date only in condensed matter physics.
Dissipation by transfer and its influence on fusion
Authors: Colucci Giulia , Trzcińska Agnieszka , Wen Pei Wei , Piasecki Ernest
Published: October 2024

A new version of the CCQEL code has been developed by upgrading the method of coupling of transfer channels during fusion and backscattering processes. In particular, the number of transfer reactions included has been increased and the dependence of the strength of transfer coupling on the transferred particle and experimental Q-value distribution was introduced. The upgraded code was employed for the investigation of the influence of transfer on the smoothing of the measured quasielastic barrier distribution (Dqe) of the 24Mg + 92Zr and 20Ne + 208Pb systems and found interesting discrepancies with respect to the standard approximations. The study with the upgraded code indicates the transfer responsible for generating strongly excited targets as the leading cause of the smearing of the barrier distribution, even in the case of negative ground state to ground state Q value (Qgg). The smoothing observed in the barrier distribution is dominated rather by one neutron transfer, despite the negative Qgg value for this reaction and the positive Qgg value for two-neutron transfer. Of particular interest is the case of the 20Ne + 208Pb, where the smoothing of the Dqe is mainly influenced by the one neutron pick-up at the beam energy above the barrier, while the one neutron pick-up and one proton stripping transfers are dominant for lower beam energy. These results highlight the importance of the transfer coupling dependence on the experimental Q-value distribution and, consequently, on the projectile kinetic energy.
Excitation energy dependency of the low-energy fission dynamics: Probing through prompt gamma-ray spectroscopy
Authors: Dey Aniruddha , Biswas D. C. , Chakraborty A. , Mukhopadhyay S.
Published: October 2024

Fission Fragment Spectroscopy (FFS) technique has been utilized to make simultaneous measurements of both the relative charge and mass yield distributions of even-even fission fragments produced from the fission of 236U at two different excitation energies, Eex. The necessary analysis has been carried out on the measured yield distributions by employing the Multimodal Random Neck Rupture Model (MM-RNRM). The relative contribution of two different types of asymmetric mode of fission – Standard I and Standard II has been extracted at Eex = 6.5 and 21.5 MeV. An attempt has been made to study the evolution of these two asymmetric fission modes with respect to the values of Eex of the concerned fissioning system at low-excitation regime. The probable evidence, although at the primitive stage, for an oscillatory behavior of the relative contributions of different low-energy fission modes with increasing values of Eex has been presented.