Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 20 de 90
1.
Small ; : e2402993, 2024 May 15.
Article En | MEDLINE | ID: mdl-38750614

2D covalent organic framework (COF) materials with extended conjugated structure and periodic columnar π-arrays exhibit promising applications in organic optoelectronics. However, there is a scarcity of reports on optoelectronic COFs, mainly due to the lack of suitable π-skeletons. Here, two multi-functional optoelectronic 2D COFs DPP-TPP-COF and DPP-TBB-COF are constructed with diketopyrrolopyrrole as electron acceptor (A), and 1,3,6,8-tetraphenylpyrene and 1,3,5-triphenylbenzene as electron donor (D) through imine bonds. Both 2D COFs showed good crystallinities and AA stacking with a rhombic framework for DPP-TPP-COF and hexagonal one for DPP-TBB-COF, respectively. The electron D-A and ordered intermolecular packing structures endow the COFs with broad UV-vis absorptions and narrow bandgaps along with suitable HOMO/LUMO energy levels, resulting in multi-functional optoelectronic properties, including photothermal conversion, supercapacitor property, and ambipolar semiconducting behavior. Among them, DPP-TPP-COF exhibits a high photothermal conversion efficiency of 47% under 660 nm laser irradiation, while DPP-TBB-COF exhibits superior specific capacitance of 384 F g-1. Moreover, P-type doping and N-type doping are achieved by iodine and tetrakis(dimethylamino)ethylene on a single host COF, resulting in ambipolar semiconducting behavior. These results provide a paradigm for the application of multi-functional optoelectronic COF materials.

2.
Front Immunol ; 15: 1361277, 2024.
Article En | MEDLINE | ID: mdl-38711522

In the late stages of the COVID-19 pandemic, there's an increasing trend in opportunistic infections, including bacterial and fungal infections. This study discusses the treatment process of two cases of cryptococcal meningitis during the COVID-19 pandemic. It highlights the importance of laboratory testing for these co-infections and stresses the need for vigilance, early diagnosis, and proactive treatment to improve patient outcomes in the post-pandemic era.


Antifungal Agents , COVID-19 , Meningitis, Cryptococcal , SARS-CoV-2 , Humans , Meningitis, Cryptococcal/drug therapy , Meningitis, Cryptococcal/diagnosis , COVID-19/complications , COVID-19/epidemiology , Male , Antifungal Agents/therapeutic use , Middle Aged , Female , Coinfection , Adult , Cryptococcus neoformans/isolation & purification , Treatment Outcome
4.
Front Oncol ; 14: 1360942, 2024.
Article En | MEDLINE | ID: mdl-38595826

Background: Von-Hipple Lindau syndrome is an uncommon autosomal dominant disorder. 17 years ago we diagnosed a young woman with VHL syndrome validated by Sanger sequencing, her family members were genetically tested as well, and 187 healthy people were randomly selected for VHL genetic testing as controls. We analyze the clinical and genetic characteristics of VHL syndrome in a Chinese lineage and with 17-year follow-up. Case presentation: A woman was finally diagnosed with VHL syndrome due to the detection of a missense mutation c.353T > C in exon 2 of the short arm of chromosome 3, which resulted in a leucine substitution at amino acid 118 of the encoded protein by a proline, which may be thought the main cause of the disease. The same mutation was observed in two other family members, their clinical symptoms are not entirely identical. However, this mutation was not found in other family members or 187 healthy controls. She clinically presented with central nervous system hemangioblastomas, clear renal cell carcinoma, and pancreatic neuroendocrine neoplasms, despite the multi-organ involvement and several relapses during the disease, the patients survive well for she was treated with aggressive surgery early in the course of the plaguing symptoms, whereas patients who are not aggressively treated have a poorer prognosis. Conclusion: The clinical presentation of VHL syndrome is atypical, and early identification and treatment of VHL syndrome is possible by genetic testing techniques. Multiple relapses occurred during the course of the disease, but early diagnosis and aggressive treatment allowed the patients to survive well.

5.
BMC Anesthesiol ; 24(1): 147, 2024 Apr 17.
Article En | MEDLINE | ID: mdl-38632505

OBJECTIVE: The aim of this study is to observe the anesthetic effect and safety of intravenous anesthesia without muscle relaxant with propofol-remifentanil combined with regional block under laryngeal mask airway in pediatric ophthalmologic surgery. METHODS: A total of 90 undergoing ophthalmic surgery were anesthetized with general anesthesia using the laryngeal mask airway without muscle relaxant. They were randomly divided into two groups: 45 children who received propofol-remifentanil intravenous anesthesia combined with regional block (LG group), and 45 children who received total intravenous anesthesia (G group). The peri-operative circulatory indicators, awakening time after general anesthesia, postoperative analgesic effect and the incidence of anesthesia-related adverse events were respectively compared between the two groups. RESULTS: All the children successfully underwent the surgical procedure. The awakening time after general anesthesia and removal time of laryngeal mask were significantly shorter in the LG group than in the G group (P < 0.05). There was no statistically significant difference in the heart rates in the perioperative period between the two groups (P > 0.05). There was no statistically significant difference in the incidence of intraoperative physical response, respiratory depression, postoperative nausea and vomiting (PONV) and emergence agitation (EA) between the two groups (P > 0.05). The pain score at the postoperative hour 2 was lower in the LG group than in the G group (P < 0.05). CONCLUSION: Propofol-remifentanil intravenous anesthesia combined with long-acting local anesthetic regional block anesthesia, combined with laryngeal mask ventilation technology without muscle relaxants, can be safely used in pediatric eye surgery to achieve rapid and smooth recovery from general anesthesia and better postoperative analgesia. This anesthesia scheme can improve the comfort and safety of children in perioperative period, and has a certain clinical popularization value.


Propofol , Child , Humans , Anesthesia, General , Anesthesia, Intravenous/methods , Anesthetics, Intravenous , Propofol/therapeutic use , Remifentanil
6.
Org Lett ; 25(31): 5774-5778, 2023 Aug 11.
Article En | MEDLINE | ID: mdl-37503938

In this work, an N-substituted diketopyrrolopyrrole (DPP) derivative Ph-DPP was synthesized, showing interaction toward Lewis alkaline anions such as F-. The typical electron-transfer-dominated anion-π interaction product Ph-DPP•- and unexpected isomer product i-Ph-DPP were both observed, and their formation mechanism was studied by density functional theory calculations, suggesting that a deprotonation initiation route is favored, which gives interesting insight for understanding the debatable role of F- in such non-covalent intermolecular interactions.

7.
Infect Drug Resist ; 16: 727-733, 2023.
Article En | MEDLINE | ID: mdl-36756612

Central nervous system infection by Balamuthia mandrillaris is a rare and severe condition, which has a fatality rate of approximately 95% and often evades timely diagnosis due to its rarity and non-specific clinical manifestations. Here, we report a case of encephalomyelomeningitis caused by B. mandrillaris in a male who presented with transient coma, nausea, and vomiting when working in a garbage dump. Initial magnetic resonance imaging (MRI) of the brain showed normal signals. Despite receiving steroids as well as antibacterial and antiviral treatment, he developed urinary and fecal dysfunction, inability to walk, and deterioration of consciousness. Both brain and spinal cord MRI revealed abnormal findings, and next-generation sequencing of the cerebrospinal fluid showed the presence of B. mandrillaris. A combination of fluconazole and albendazole was administered; however, the patient deteriorated gradually and died 30 days after the onset. We suggest the unbiased metagenomic sequencing of the affected tissues/CSF in patients with CNS infections that are difficult to diagnose or treat, and multiple tests at different stages of the disease may be required.

8.
Front Oncol ; 12: 892056, 2022.
Article En | MEDLINE | ID: mdl-35965542

Glioma is one of the most fatal primary brain tumors, and it is well-known for its difficulty in diagnosis and management. Medical imaging techniques such as magnetic resonance imaging (MRI), positron emission tomography (PET), and spectral imaging can efficiently aid physicians in diagnosing, treating, and evaluating patients with gliomas. With the increasing clinical records and digital images, the application of artificial intelligence (AI) based on medical imaging has reduced the burden on physicians treating gliomas even further. This review will classify AI technologies and procedures used in medical imaging analysis. Additionally, we will discuss the applications of AI in glioma, including tumor segmentation and classification, prediction of genetic markers, and prediction of treatment response and prognosis, using MRI, PET, and spectral imaging. Despite the benefits of AI in clinical applications, several issues such as data management, incomprehension, safety, clinical efficacy evaluation, and ethical or legal considerations, remain to be solved. In the future, doctors and researchers should collaborate to solve these issues, with a particular emphasis on interdisciplinary teamwork.

9.
Analyst ; 147(12): 2802-2808, 2022 Jun 13.
Article En | MEDLINE | ID: mdl-35611629

Surface enhanced Raman scattering (SERS) is an ultrasensitive analytic technique. However, the application of SERS in quantitative analysis usually suffers from poor reliability due to the limitations of currently developed SERS substrates. In the present work, aggregated gold nanoparticles (a-AuNPs) fabricated by Ca2+-mediated assembly are dispersed in polyvinyl alcohol solution to prepare a novel hydrogel SERS chip through a physical crosslinking method. Taking advantage of the uniform distribution of SERS active a-AuNPs in the three-dimension hydrogel and the excellent barrier effect of hydrogel towards oxygen and macromolecules, the obtained hydrogel SERS chips show many outstanding advantages including high sensitivity, good repeatability, long-term stability, and a robust anti-interference ability. These advantages enable hydrogel SERS chips to be used to quantitatively analyse some complex samples without complex sample preprocessing. As a model, the hydrogel SERS chips are used for the detection of triazophos and phosmet in orange samples. The good recoveries suggest good applicability of the hydrogel SERS chips in food safety detection. This work provides a reliable and convenient platform for the quick detection and on-site monitoring of chemical contaminants and would promote greatly the performance of SERS techniques in quantitative analysis.


Metal Nanoparticles , Pesticides , Gold/chemistry , Hydrogels , Metal Nanoparticles/chemistry , Organophosphorus Compounds , Pesticides/analysis , Reproducibility of Results , Spectrum Analysis, Raman/methods
11.
J Assoc Res Otolaryngol ; 23(3): 435-453, 2022 06.
Article En | MEDLINE | ID: mdl-35378621

Vestibular evoked myogenic potentials (VEMPs) are routinely used to test otolith function, but which specific vestibular afferent neurons and central circuits are activated by auditory frequency VEMP stimuli remains unclear. To examine this question, we analyzed the sensitivity of individual vestibular afferents in adult Sprague-Dawley rats to tone bursts delivered at 9 frequencies (125-4000 Hz) and 3 intensity levels (60, 70, 80 dB SL re: acoustic brainstem response (ABR) threshold). Afferent neuron tone sensitivity was quantified by the cumulative probability of evoking a spike (CPE). Based on a threshold CPE of 0.1, acoustic stimuli in the present study evoked responses in 78.2 % (390/499) of otolith afferent neurons vs. 48.4 % (431/891) of canal afferent neurons. Organ-specific vestibular inputs to the central nervous system in response to tone bursts differ based on intensity and frequency content of the stimulus. At frequencies below 500 Hz, tone bursts primarily activated both otolith afferents, even at the highest intensity tested (80 dB SL re ABR threshold). At 1500 Hz, however, tone bursts activated the canal and otolith afferents at the moderate and high intensities tested (70, 80 dB SL), but activated only otolith afferents at the low intensity tested (60 dB SL). Within an end organ, diversity of sensitivity between individual afferent neurons correlated with spontaneous discharge rate and regularity. Examination of inner ear fluid mechanics in silico suggests that the frequency response and preferential activation of the otolith organs likely arise from inner ear fluid motion trapped near the oval and round windows. These results provide insight into understanding the mechanisms of sound activation of the vestibular system and developing novel discriminative VEMP testing protocols and interpretative guidelines in humans.


Otolithic Membrane , Vestibular Evoked Myogenic Potentials , Acoustic Stimulation/methods , Acoustics , Animals , Otolithic Membrane/physiology , Rats , Rats, Sprague-Dawley , Vestibular Evoked Myogenic Potentials/physiology
12.
Biotechnol Appl Biochem ; 69(6): 2733-2744, 2022 Dec.
Article En | MEDLINE | ID: mdl-34994979

Chaetominine (CHA), an alkaloid with a biological activity obtained from Aspergillus fumigatus CY018, has strong anticancer activity against the human leukemia cells. However, its physiological and biochemical research is limited by CHA yield in the liquid-state fermentation, which is a problem that urgently needs effective biological solution. In this work, Ca2+ and Al3+ were found to have a strong promoting effect on CHA production after multiple metal ions screening. Then, the addition condition of Ca2+ and Al3+ was, respectively, optimized CHA production and dry cell weight. The intermediate metabolites were increased with coaddition of Ca2+ and Al3+ . The activities of key enzymes of DAHPs, AroAs, and TrpCs in the CHA biosynthesis pathway were improved by 3.58-, 3.60-, and 3.34-fold, respectively. Meanwhile, the transcription level of laeA, dahp, cs, and trpC was upregulated by 3.22-, 12.65-, 5.58-, and 6.99-fold, respectively, by coaddition of Ca2+ and Al3+ . Additionally, the fermentation strategy was successfully scaled up to a 5-L bioreactor, in which CHA production could attain 75.6 mg/L at 336 h. This work demonstrated that Ca2+ and Al3+ coaddition was an effective strategy for increasing CHA production, and the information obtained might be useful in the fermentation of filamentous fungi with the addition of metal ions.


Aspergillus fumigatus , Bioreactors , Humans , Fermentation , Aspergillus fumigatus/metabolism , Indole Alkaloids/metabolism , Indole Alkaloids/pharmacology
13.
Neural Regen Res ; 17(1): 115-121, 2022 Jan.
Article En | MEDLINE | ID: mdl-34100446

Exposure to explosive shockwave often leads to blast-induced traumatic brain injury in military and civilian populations. Unprotected ears are most often damaged following exposure to blasts. Although there is an association between tympanic membrane perforation and TBI in blast exposure victims, little is known about how and to what extent blast energy is transmitted to the central nervous system via the external ear canal. The present study investigated whether exposure to blasts directed through the ear canal causes brain injury in Long-Evans rats. Animals were exposed to a single blast (0-30 pounds per square inch (psi)) through the ear canal, and brain injury was evaluated by histological and behavioral outcomes at multiple time-points. Blast exposure not only caused tympanic membrane perforation but also produced substantial neuropathological changes in the brain, including increased expression of c-Fos, induction of a profound chronic neuroinflammatory response, and apoptosis of neurons. The blast-induced injury was not limited only to the brainstem most proximal to the source of the blast, but also affected the forebrain including the hippocampus, amygdala and the habenula, which are all involved in cognitive functions. Indeed, the animals exhibited long-term neurological deficits, including signs of anxiety in open field tests 2 months following blast exposure, and impaired learning and memory in an 8-arm maze 12 months following blast exposure. These results suggest that the unprotected ear canal provides a locus for blast waves to cause TBI. This study was approved by the Institutional Animal Care and Use Committee at the University of Mississippi Medical Center (Animal protocol# 0932E, approval date: September 30, 2016 and 0932F, approval date: September 27, 2019).

14.
Front Neurosci ; 15: 741571, 2021.
Article En | MEDLINE | ID: mdl-34720863

Vestibular evoked myogenic potentials (VEMP) have been used to assess otolith function in clinics worldwide. However, there are accumulating evidence suggesting that the clinically used sound stimuli activate not only the otolith afferents, but also the canal afferents, indicating canal contributions to the VEMPs. To better understand the neural mechanisms underlying the VEMPs and develop discriminative VEMP protocols, we further examined sound-evoked responses of the vestibular nucleus neurons and the abducens neurons, which have the interneurons and motoneurons of the vestibulo-ocular reflex (VOR) pathways. Air-conducted clicks (50-80 dB SL re ABR threshold, 0.1 ms duration) or tone bursts (60-80 dB SL, 125-4,000 Hz, 8 ms plateau, 1 ms rise/fall) were delivered to the ears of Sprague-Dawley or Long-Evans rats. Among 425 vestibular nucleus neurons recorded in anesthetized rats and 18 abducens neurons recorded in awake rats, sound activated 35.9% of the vestibular neurons that increased discharge rates for ipsilateral head rotation (Type I neuron), 15.7% of the vestibular neurons that increased discharge rates for contralateral head rotation (Type II neuron), 57.2% of the vestibular neurons that did not change discharge rates during head rotation (non-canal neuron), and 38.9% of the abducens neurons. Sound sensitive vestibular nucleus neurons and abducens neurons exhibited characteristic tuning curves that reflected convergence of canal and otolith inputs in the VOR pathways. Tone bursts also evoked well-defined eye movements that increased with tone intensity and duration and exhibited peak frequency of ∼1,500 Hz. For the left eye, tone bursts evoked upward/rightward eye movements for ipsilateral stimulation, and downward/leftward eye movements for contralateral stimulation. These results demonstrate that sound stimulation results in activation of the canal and otolith VOR pathways that can be measured by eye tracking devices to develop discriminative tests of vestibular function in animal models and in humans.

15.
Biomed Res Int ; 2021: 5568696, 2021.
Article En | MEDLINE | ID: mdl-34337028

INTRODUCTION: To date, identifying emergent large vessel occlusion (ELVO) patients in the prehospital stage is important but still challenging. In this present study, we aimed to design a modified prehospital acute stroke severity (mPASS) scale to identify ELVO patients and compared the scale to the PASS scale which has been published. METHODS: We retrospectively evaluated a consecutive cohort of acute ischemic stroke (AIS) in our stroke unit who visited the emergercy department. These patients underwent CT angiography (CTA), MR angiography (MRA), or digital subtraction angiography (DSA) at admission. The mPASS scale was calculated based on the National Institutes of Health Stroke Scale (NIHSS) items retrospectively, including the level of consciousness commands, gaze, arm weakness, and aphasia/dysarthria. Receiver operating characteristic (ROC) analysis was used to obtain the area under the curve (AUC) of the mPASS scale, NIHSS, and PASS scale. U-statistics was used to compare the AUC of the mPASS scale to the NIHSS and PASS scale. RESULTS: A total of 382 AIS patients were enrolled. The AUC and specificity of the mPASS scale (0.92, 84.4) were all higher than those of the PASS scale. Cortical symptoms such as gaze palsy and consciousness disorder were more specific indicators for ELVO than motor deficits. CONCLUSIONS: The mPASS scale had a better discrimination for identifying ELVO than the PASS scale in our retrospective cohort. It might predict ELVO in an effective and simple way for paramedics in the prehospital triage stage or emergency stage. Moreover, cortical symptoms might have relatively high specificities to predict ELVO on their own.


Arterial Occlusive Diseases/diagnosis , Hospitalization , Severity of Illness Index , Stroke/pathology , Aged , Discriminant Analysis , Female , Humans , Male , Predictive Value of Tests , Sensitivity and Specificity
16.
PLoS One ; 16(8): e0251323, 2021.
Article En | MEDLINE | ID: mdl-34398900

The recent advances in gene chip technology have led to the identification of multiple metabolism-related genes that are closely associated with colorectal cancer (CRC). Nevertheless, none of these genes could accurately diagnose or predict CRC. The prognosis of CRC has been made by previous prognostic models constructed by using multiple genes, however, the predictive function of multi-gene prognostic models using metabolic genes for the CRC prognosis remains unexplored. In this study, we used the TCGA-CRC cohort as the test dataset and the GSE39582 cohort as the experimental dataset. Firstly, we constructed a prognostic model using metabolic genes from the TCGA-CRC cohort, which were also associated with CRC prognosis. We analyzed the advantages of the prognostic model in the prognosis of CRC and its regulatory mechanism of the genes associated with the model. Secondly, the outcome of the TCGA-CRC cohort analysis was validated using the GSE39582 cohort. We found that the prognostic model can be employed as an independent prognostic risk factor for estimating the CRC survival rate. Besides, compared with traditional clinical pathology, it can precisely predict CRC prognosis as well. The high-risk group of the prognostic model showed a substantially lower survival rate as compared to the low-risk group. In addition, gene enrichment analysis of metabolic genes showed that genes in the prognostic model are enriched in metabolism and cancer-related pathways, which may explain its underlying mechanism. Our study identified a novel metabolic profile containing 11 genes for prognostic prediction of CRC. The prognostic model may unravel the imbalanced metabolic microenvironment, and it might promote the development of biomarkers for predicting treatment response and streamlining metabolic therapy in CRC.


Colorectal Neoplasms , Gene Expression Regulation, Neoplastic , Genes, Neoplasm , Models, Biological , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/mortality , Databases, Nucleic Acid , Disease-Free Survival , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Risk Factors , Survival Rate
17.
World Neurosurg ; 151: e918-e926, 2021 07.
Article En | MEDLINE | ID: mdl-33991729

OBJECTIVE: Basilar artery occlusion (BAO) is a severe condition with high mortality. However, surgical procedures and outcomes of BAO with different pathologic subtypes have not been fully clarified. This study compared the surgical procedures and clinical outcomes of mechanical thrombectomy in different subtypes of BAO. METHODS: Eighty-six patients with acute BAO receiving endovascular treatment between October 2015 and July 2019 were retrospectively analyzed and placed in 3 groups: pure embolism (group 1), arterial-arterial embolism from steno-occlusion of the tandem vertebral artery (group 2), and in situ atherosclerotic thrombosis (group 3). Recanalization rates, procedure times, surgical characteristics, and clinical outcomes were analyzed. RESULTS: Groups 1, 2, and 3 included 33 (38.4%), 17 (19.8%), and 36 (41.9%) patients, respectively. The overall successful recanalization rate was 95.3%, and the good outcome rate was 61.6%. The procedure time in group 1 was shorter than the time in groups 2 and 3 (P < 0.001). The clinical good outcome rate was higher in group 2 than in group 1 (88.2% vs. 54.5%; P = 0.017). Groups 1 and 3 had similar good outcome rates (54.5% vs. 55.6%; P = 0.933). Twenty-seven patients received stent angioplasty: 10 of 17 in group 2 (58.8%) and 17 of 36 in group 3 (47.2%). CONCLUSIONS: The outcome of endovascular treatment for BAO varies among patients with different pathologic mechanisms. Patients with embolism from tandem vertebral artery steno-occlusion achieved the best outcomes. Rescue treatment was more common in patients with embolic BAO with tandem vertebral artery steno-occlusion and BAO with in situ atherosclerotic thrombosis.


Endovascular Procedures/methods , Vertebrobasilar Insufficiency/pathology , Vertebrobasilar Insufficiency/surgery , Adult , Aged , Aged, 80 and over , Female , Humans , Intracranial Arteriosclerosis/complications , Intracranial Arteriosclerosis/pathology , Intracranial Arteriosclerosis/surgery , Intracranial Embolism/pathology , Intracranial Embolism/surgery , Male , Middle Aged , Retrospective Studies , Thrombectomy/methods , Treatment Outcome , Vertebrobasilar Insufficiency/etiology
18.
Materials (Basel) ; 14(9)2021 Apr 26.
Article En | MEDLINE | ID: mdl-33925805

The application of recycled coarse aggregate (RCA) made from waste concrete to replace natural coarse aggregate (NCA) in concrete structures can essentially reduce the excessive consumption of natural resources and environmental pollution. Similar to normal concrete structures, recycled concrete structures would also suffer from the damage of carbonation, which leads to the deterioration of durability and the reduction of service life. This paper presents the experimental results of the cubic compressive strength, the static elastic modulus and the stress-strain relation of recycled coarse aggregate concrete (RAC) after carbonation. The results show that the cubic compressive strength and the static elastic modulus of carbonated RAC gradually increased with the carbonation depth. The uncarbonated and fully carbonated RAC show smaller static elastic modulus than natural aggregate concrete (NAC). As the carbonation depth increased, the peak stress increased, while the peak strain decreased and the descending part of the curves gradually became steeper. As the content of RCA became larger, the peak stress decreased, while the peak strain increased and the descending part of the curves gradually became steeper. An equation for stress-strain curves of RAC after carbonation was proposed, and it was in good agreement with the test results.

19.
Front Comput Neurosci ; 15: 637144, 2021.
Article En | MEDLINE | ID: mdl-33679359

The convolutional neural networks (CNNs) are a powerful tool of image classification that has been widely adopted in applications of automated scene segmentation and identification. However, the mechanisms underlying CNN image classification remain to be elucidated. In this study, we developed a new approach to address this issue by investigating transfer of learning in representative CNNs (AlexNet, VGG, ResNet-101, and Inception-ResNet-v2) on classifying geometric shapes based on local/global features or invariants. While the local features are based on simple components, such as orientation of line segment or whether two lines are parallel, the global features are based on the whole object such as whether an object has a hole or whether an object is inside of another object. Six experiments were conducted to test two hypotheses on CNN shape classification. The first hypothesis is that transfer of learning based on local features is higher than transfer of learning based on global features. The second hypothesis is that the CNNs with more layers and advanced architectures have higher transfer of learning based global features. The first two experiments examined how the CNNs transferred learning of discriminating local features (square, rectangle, trapezoid, and parallelogram). The other four experiments examined how the CNNs transferred learning of discriminating global features (presence of a hole, connectivity, and inside/outside relationship). While the CNNs exhibited robust learning on classifying shapes, transfer of learning varied from task to task, and model to model. The results rejected both hypotheses. First, some CNNs exhibited lower transfer of learning based on local features than that based on global features. Second the advanced CNNs exhibited lower transfer of learning on global features than that of the earlier models. Among the tested geometric features, we found that learning of discriminating inside/outside relationship was the most difficult to be transferred, indicating an effective benchmark to develop future CNNs. In contrast to the "ImageNet" approach that employs natural images to train and analyze the CNNs, the results show proof of concept for the "ShapeNet" approach that employs well-defined geometric shapes to elucidate the strengths and limitations of the computation in CNN image classification. This "ShapeNet" approach will also provide insights into understanding visual information processing the primate visual systems.

20.
Hear Res ; 404: 108202, 2021 05.
Article En | MEDLINE | ID: mdl-33621791

The guinea pig is a commonly-used animal model in hearing research, as their audible frequency range is similar to that of humans, and they possess comparatively large cochleae among rodents. Numerous studies have investigated the ototoxic effects of cisplatin in guinea pigs, but these have been mostly limited to single high-dose bolus injections of cisplatin. This method of drug administration is not consistent with human treatment schedules, and therefore lacks translational value to clinical applications. We tested several different cisplatin dosing schedules in guinea pigs based on common research based and clinical regimens, measuring the resulting hearing loss and morbidity (weight loss). We propose a dosing paradigm of once-weekly 4 mg/kg cisplatin injections for three weeks to best mimic clinical treatment schedules. This method resulted in a configuration of hearing loss similar to what is observed in humans along with minimal changes in weight.


Hearing Loss , Ototoxicity , Animals , Antineoplastic Agents/toxicity , Cisplatin/toxicity , Evoked Potentials, Auditory, Brain Stem/drug effects , Guinea Pigs , Hearing , Hearing Loss/chemically induced
...