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1.
Nature ; 626(8000): 765-771, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38383627

ABSTRACT

Photonic bound states in the continuum (BICs), embedded in the spectrum of free-space waves1,2 with diverging radiative quality factor, are topologically non-trivial dark modes in open-cavity resonators that have enabled important advances in photonics3,4. However, it is particularly challenging to achieve maximum near-field enhancement, as this requires matching radiative and non-radiative losses. Here we propose the concept of supercritical coupling, drawing inspiration from electromagnetically induced transparency in near-field coupled resonances close to the Friedrich-Wintgen condition2. Supercritical coupling occurs when the near-field coupling between dark and bright modes compensates for the negligible direct far-field coupling with the dark mode. This enables a quasi-BIC field to reach maximum enhancement imposed by non-radiative loss, even when the radiative quality factor is divergent. Our experimental design consists of a photonic-crystal nanoslab covered with upconversion nanoparticles. Near-field coupling is finely tuned at the nanostructure edge, in which a coherent upconversion luminescence enhanced by eight orders of magnitude is observed. The emission shows negligible divergence, narrow width at the microscale and controllable directivity through input focusing and polarization. This approach is relevant to various physical processes, with potential applications for light-source development, energy harvesting and photochemical catalysis.

2.
Am J Hum Genet ; 110(7): 1098-1109, 2023 07 06.
Article in English | MEDLINE | ID: mdl-37301203

ABSTRACT

Although the best-known spinocerebellar ataxias (SCAs) are triplet repeat diseases, many SCAs are not caused by repeat expansions. The rarity of individual non-expansion SCAs, however, has made it difficult to discern genotype-phenotype correlations. We therefore screened individuals who had been found to bear variants in a non-expansion SCA-associated gene through genetic testing, and after we eliminated genetic groups that had fewer than 30 subjects, there were 756 subjects bearing single-nucleotide variants or deletions in one of seven genes: CACNA1A (239 subjects), PRKCG (175), AFG3L2 (101), ITPR1 (91), STUB1 (77), SPTBN2 (39), or KCNC3 (34). We compared age at onset, disease features, and progression by gene and variant. There were no features that reliably distinguished one of these SCAs from another, and several genes-CACNA1A, ITPR1, SPTBN2, and KCNC3-were associated with both adult-onset and infantile-onset forms of disease, which also differed in presentation. Nevertheless, progression was overall very slow, and STUB1-associated disease was the fastest. Several variants in CACNA1A showed particularly wide ranges in age at onset: one variant produced anything from infantile developmental delay to ataxia onset at 64 years of age within the same family. For CACNA1A, ITPR1, and SPTBN2, the type of variant and charge change on the protein greatly affected the phenotype, defying pathogenicity prediction algorithms. Even with next-generation sequencing, accurate diagnosis requires dialogue between the clinician and the geneticist.


Subject(s)
Cerebellar Ataxia , Spinocerebellar Ataxias , Humans , Spinocerebellar Ataxias/genetics , Spinocerebellar Ataxias/diagnosis , Cerebellar Ataxia/genetics , Phenotype , Ataxia/genetics , Genetic Testing , ATPases Associated with Diverse Cellular Activities/genetics , ATP-Dependent Proteases/genetics , Ubiquitin-Protein Ligases/genetics
3.
Hum Mol Genet ; 31(12): 2010-2022, 2022 06 22.
Article in English | MEDLINE | ID: mdl-35015850

ABSTRACT

Frataxin (FXN) deficiency is responsible for Friedreich's ataxia (FRDA) in which, besides the characteristic features of spinocerebellar ataxia, two thirds of patients develop hypertrophic cardiomyopathy that often progresses to heart failure and premature death. Different mechanisms might underlie FRDA pathogenesis. Among them, the role of miRNAs deserves investigations. We carried out an miRNA PCR-array analysis of plasma samples of early-, intermediate- and late-onset FRDA groups, defining a set of 30 differentially expressed miRNAs. Hsa-miR223-3p is the only miRNA shared between the three patient groups and appears upregulated in all of them. The up-regulation of hsa-miR223-3p was further validated in all enrolled patients (n = 37, Fc = +2.3; P < 0.0001). Using a receiver operating characteristic curve analysis, we quantified the predictive value of circulating hsa-miR223-3p for FRDA, obtaining an area under the ROC curve value of 0.835 (P < 0.0001) for all patients. Interestingly, we found a significant positive correlation between hsa-miR223-3p expression and cardiac parameters in typical FRDA patients (onset < 25 years). Moreover, a significant negative correlation between hsa-miR223-3p expression and HAX-1 (HCLS1-associated protein X-1) at mRNA and protein level was observed in all FRDA patients. In silico analyses suggested HAX-1 as a target gene of hsa-miR223-3p. Accordingly, we report that HAX-1 is negatively regulated by hsa-miR223-3p in cardiomyocytes (AC16) and neurons (SH-SY5Y), which are critically affected cell types in FRDA. This study describes for the first time the association between hsa-miR223-3p and HAX-1 expression in FRDA, thus supporting a potential role of this microRNA as non-invasive epigenetic biomarker for FRDA.


Subject(s)
Adaptor Proteins, Signal Transducing , Friedreich Ataxia , MicroRNAs , Neuroblastoma , Adaptor Proteins, Signal Transducing/genetics , Friedreich Ataxia/pathology , Humans , MicroRNAs/blood , Myocytes, Cardiac/metabolism , Neuroblastoma/metabolism , RNA, Messenger/genetics
4.
Mult Scler ; 30(3): 325-335, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38333907

ABSTRACT

BACKGROUND: The increasing knowledge about multiple sclerosis (MS) pathophysiology has reinforced the need for an improved description of disease phenotypes, connected to disease biology. Growing evidence indicates that complex diseases constitute phenotypical and genetic continuums with "simple," monogenic disorders, suggesting shared pathomechanisms. OBJECTIVES: The objective of this study was to depict a novel MS phenotypical framework leveraging shared physiopathology with Mendelian diseases and to identify phenotype-specific candidate drugs. METHODS: We performed an enrichment testing of MS-associated variants with Mendelian disorders genes. We defined a "MS-Mendelian network," further analyzed to define enriched phenotypic subnetworks and biological processes. Finally, a network-based drug screening was implemented. RESULTS: Starting from 617 MS-associated loci, we showed a significant enrichment of monogenic diseases (p < 0.001). We defined an MS-Mendelian molecular network based on 331 genes and 486 related disorders, enriched in four phenotypic classes: neurologic, immunologic, metabolic, and visual. We prioritized a total of 503 drugs, of which 27 molecules active in 3/4 phenotypical subnetworks and 140 in subnetwork pairs. CONCLUSION: The genetic architecture of MS contains the seeds of pathobiological multiplicities shared with immune, neurologic, metabolic and visual monogenic disorders. This result may inform future classifications of MS endophenotypes and support the development of new therapies in both MS and rare diseases.


Subject(s)
Multiple Sclerosis , Humans , Phenotype , Genome-Wide Association Study , Genetic Predisposition to Disease
5.
Eur J Neurol ; 30(9): 2736-2744, 2023 09.
Article in English | MEDLINE | ID: mdl-37294976

ABSTRACT

BACKGROUND AND PURPOSE: The overall disability in patients with relapsing-remitting multiple sclerosis is likely to be partly rather than entirely attributed to relapse. MATERIALS AND METHODS: The aim was to investigate the determinants of recovery from first relapse and relapse-associated worsening (RAW) in relapsing-remitting multiple sclerosis patients from the Italian MS Registry during a 5-year epoch from the beginning of first-line disease-modifying therapy. To determine recovery, the functional system (FS) score was used to calculate the difference between the score on the date of maximum improvement and the score before the onset of relapse. Incomplete recovery was defined as a combination of partial (1 point in one FS) and poor recovery (2 points in one FS or 1 point in two FSs or any other higher combination). RAW was indicated by a confirmed disability accumulation measured by the Expanded Disability Status Scale score confirmed 6 months after the first relapse. RESULTS: A total of 767 patients had at least one relapse within 5 years of therapy. Of these patients, 57.8% experienced incomplete recovery. Age (odds ratio [OR] 1.02, 95% confidence interval [CI] 1.01-1.04; p = 0.007) and pyramidal phenotype were associated with incomplete recovery (OR = 2.1, 95% CI 1.41-3.14; p < 0.001). RAW was recorded in 179 (23.3%) patients. Age (OR = 1.02, 95% CI 1.01-1.04; p = 0.029) and pyramidal phenotype (OR = 1.84, 95% CI 1.18-2.88; p = 0.007) were the strongest predictors in the multivariable model. CONCLUSIONS: Age and pyramidal phenotype were the strongest determinants of RAW in early disease epochs.


Subject(s)
Multiple Sclerosis, Relapsing-Remitting , Multiple Sclerosis , Humans , Multiple Sclerosis, Relapsing-Remitting/drug therapy , Chronic Disease , Recurrence
6.
Int J Mol Sci ; 24(6)2023 Mar 19.
Article in English | MEDLINE | ID: mdl-36982913

ABSTRACT

The management of patients with metastatic colorectal cancer (mCRC) has the continuum of care as the treatment paradigm. To date, trifluridine/tipiracil, a biochemically modulated fluoropyrimidine, and regorafenib, a multi-kinase inhibitor, remain the main options for the majority of patients who progressed to standard doublet- or triplet-based chemotherapies, although a tailored approach could be indicated in certain circumstances. Being highly selective for vascular endothelial growth factor receptor (VEGFR)-1, -2 and -3, fruquintinib demonstrated a strong anti-tumor activity in preclinical models and received approval from China's National Medical Products Administration (NMPA) in 2018 for the treatment of patients with chemo-refractory mCRC. The approval was based on the results of the phase III FRESCO trial. Then, in order to overcome geographic differences in clinical practice, the FRESCO-2 trial was conducted in the US, Europe, Japan, and Australia. In a heavily pretreated patient population, the study met its primary endpoint, demonstrating an advantage of fruquintinib over a placebo in overall survival (OS). Here, we review the clinical development of fruquintinib and its perspectives in gastrointestinal cancers. Then, we discuss the introduction of fruquintinib in the continuum of care of CRC paying special attention to unmet needs, including the identification of cross-resistant and potentially susceptible populations, evaluation of radiological response, and identification of novel biomarkers of clinical benefit.


Subject(s)
Benzofurans , Colonic Neoplasms , Colorectal Neoplasms , Rectal Neoplasms , Humans , Colorectal Neoplasms/pathology , Vascular Endothelial Growth Factor A/therapeutic use , Benzofurans/therapeutic use , Benzofurans/pharmacology , Colonic Neoplasms/drug therapy , Rectal Neoplasms/drug therapy , Continuity of Patient Care
7.
Int J Mol Sci ; 24(7)2023 Mar 23.
Article in English | MEDLINE | ID: mdl-37047023

ABSTRACT

Huntington's disease (HD) is characterized by clinical motor impairment (e.g., involuntary movements, poor coordination, parkinsonism), cognitive deficits, and psychiatric symptoms. An inhered expansion of the CAG triplet in the huntingtin gene causing a pathogenic gain-of-function of the mutant huntingtin (mHTT) protein has been identified. In this review, we focus on known biomarkers (e.g., mHTT, neurofilament light chains) and on new biofluid biomarkers that can be quantified in plasma or peripheral blood mononuclear cells from mHTT carriers. Circulating biomarkers may fill current unmet needs in HD management: better stratification of patients amenable to etiologic treatment; the initiation of preventive treatment in premanifest HD; and the identification of peripheral pathogenic central nervous system cascades.


Subject(s)
Cognition Disorders , Cognitive Dysfunction , Huntington Disease , Humans , Huntington Disease/diagnosis , Huntington Disease/genetics , Huntington Disease/metabolism , Leukocytes, Mononuclear/metabolism , Cognition Disorders/etiology , Biomarkers , Cognitive Dysfunction/complications , Huntingtin Protein/genetics , Huntingtin Protein/metabolism
8.
Medicina (Kaunas) ; 59(2)2023 Feb 13.
Article in English | MEDLINE | ID: mdl-36837553

ABSTRACT

Background and objectives: Otoferlin is a multi-C2 domain protein implicated in neurotransmitter-containing vesicle release and replenishment of the cochlear inner hair cell (IHC) synapses. Mutations in the OTOF gene have been associated with two different clinical phenotypes: a prelingual severe-to-profound sensorineural hearing loss (ANSD-DFNB9); and the peculiar temperature-sensitive auditory neuropathy (TS-ANSD), characterized by a baseline mild-to-moderate hearing threshold that worsens to severe-to-profound when the body temperature rises that returns to a baseline a few hours after the temperature has fallen again. The latter clinical phenotype has been described only with a few OTOF variants with an autosomal recessive biallelic pattern of inheritance. Case report: A 7-year-old boy presented a picture compatible with TS-ANSD exacerbated by febrile states or physical exercise with mild-to-moderate hearing loss at low and medium frequencies and a decrease in speech discrimination that worsened with an unfavorable speech-to-noise ratio. Otoacoustic emissions (OAEs) were present whereas auditory brainstem responses (ABRs) evoked by a click or tone-burst were generally absent. No inner ear malformations were described from the CT scan or MRI. Next-generation sequencing (NGS) of the known deafness genes and multi-phasic bioinformatic analyses of the data detected in OTOF a c.2521G>A missense variant and the deletion of 7.4 Kb, which was confirmed by array-comparative genomic hybridization (array-CGH). The proband's parents, who were asymptomatic, were tested by Sanger sequencing and the father presented the c.2521G>A missense variant. Conclusions: The picture presented by the patient was compatible with OTOF-induced TS-ANSD. OTOF has been generally associated with an autosomal recessive biallelic pattern of inheritance; in this clinical report, two pathogenic variants never previously associated with TS-ANSD were described.


Subject(s)
Hearing Loss, Central , Hearing Loss, Sensorineural , Humans , Comparative Genomic Hybridization , Hearing Loss, Central/genetics , Hearing Loss, Sensorineural/genetics , Membrane Proteins/genetics , Mutation , Temperature , Male , Child
9.
Hum Mol Genet ; 29(3): 471-482, 2020 02 01.
Article in English | MEDLINE | ID: mdl-31943004

ABSTRACT

Frataxin deficiency, responsible for Friedreich's ataxia (FRDA), is crucial for cell survival since it critically affects viability of neurons, pancreatic beta cells and cardiomyocytes. In FRDA, the heart is frequently affected with typical manifestation of hypertrophic cardiomyopathy, which can progress to heart failure and cause premature death. A microarray analysis performed on FRDA patient's lymphoblastoid cells stably reconstituted with frataxin, indicated HS-1-associated protein X-1 (HAX-1) as the most significantly upregulated transcript (FC = +2, P < 0.0006). quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) and western blot analysis performed on (I) HEK293 stably transfected with empty vector compared to wild-type frataxin and (II) lymphoblasts from FRDA patients show that low frataxin mRNA and protein expression correspond to reduced levels of HAX-1. Frataxin overexpression and silencing were also performed in the AC16 human cardiomyocyte cell line. HAX-1 protein levels are indeed regulated through frataxin modulation. Moreover, correlation between frataxin and HAX-1 was further evaluated in peripheral blood mononuclear cells (PBMCs) from FRDA patients and from non-related healthy controls. A regression model for frataxin which included HAX-1, group membership and group* HAX-1 interaction revealed that frataxin and HAX-1 are associated both at mRNA and protein levels. Additionally, a linked expression of FXN, HAX-1 and antioxidant defence proteins MnSOD and Nrf2 was observed both in PBMCs and AC16 cardiomyocytes. Our results suggest that HAX-1 could be considered as a potential biomarker of cardiac disease in FRDA and the evaluation of its expression might provide insights into its pathogenesis as well as improving risk stratification strategies.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Cardiomyopathy, Hypertrophic/pathology , Friedreich Ataxia/complications , Gene Expression Regulation , Heart Failure/pathology , Iron-Binding Proteins/metabolism , Myocytes, Cardiac/pathology , Adaptor Proteins, Signal Transducing/genetics , Adult , Aged , Cardiomyopathy, Hypertrophic/etiology , Cardiomyopathy, Hypertrophic/metabolism , Female , Heart Failure/etiology , Heart Failure/metabolism , Humans , Iron-Binding Proteins/genetics , Leukocytes, Mononuclear/metabolism , Leukocytes, Mononuclear/pathology , Male , Middle Aged , Myocytes, Cardiac/metabolism , Young Adult , Frataxin
10.
Neuroepidemiology ; 56(3): 212-218, 2022.
Article in English | MEDLINE | ID: mdl-35636410

ABSTRACT

OBJECTIVE: The aim of this study was to estimate the Friedreich's ataxia (FRDA) prevalence in a highly populated region of Italy (previous studies in small geographic areas gave a largely variable prevalence) and to define the patients' molecular and clinical characteristics. METHODS: For the point-prevalence study, we considered patients belonging to families with a molecular diagnosis of FRDA and resident in Latium on 1 January 2019. The crude prevalence of FRDA, specific for age and sex, was calculated and standardized for age using the Italian population. Moreover, we investigated possible correlations among patients' genetic profile, symptoms, and age of onset. RESULTS: We identified 63 FRDA patients; the crude prevalence for total, males, and females were 1.07 (95% CI: 0.81-1.37), 0.81 (95% CI: 0.54-1.22), and 1.32 (95% CI: 0.97-1.79), per 100,000 inhabitants. We divided FRDA patients by three age-at-onset groups (early-EOFA 73%; late-LOFA 11.1%; very late-VLOFA 15.9%) and found significant differences in the scale for the assessment and rating of ataxia (SARA; p = 0.001), a biased distribution of the shorter allele (p = 0.001), an excess of scoliosis and cardiomyopathy (p = 0.001) in EOFA. To determine the contribution of patients' molecular and clinical characteristics to the annual rate of progression, we performed a multivariate regression analysis that gave an R2 value of 45.3%. CONCLUSIONS: We estimated the crude and standardized prevalence of FRDA in Latium. A clinical classification (EOFA, LOFA, VLOFA) gave significant correlations. This epidemiological estimate allows monitoring disease prevalence over time in cohort studies and/or for developing disease registry.


Subject(s)
Friedreich Ataxia , Cohort Studies , Cross-Sectional Studies , Female , Friedreich Ataxia/diagnosis , Friedreich Ataxia/epidemiology , Friedreich Ataxia/genetics , Humans , Italy/epidemiology , Male , Prevalence
11.
J Med Genet ; 58(7): 475-483, 2021 07.
Article in English | MEDLINE | ID: mdl-32737135

ABSTRACT

BACKGROUND: Dominant and recessive variants in the KIF1A gene on chromosome 2q37.3 are associated with several phenotypes, although only three syndromes are currently listed in the OMIM classification: hereditary sensory and autonomic neuropathy type 2 and spastic paraplegia type 30, both recessively inherited, and mental retardation type 9 with dominant inheritance. METHODS: In this retrospective multicentre study, we describe the clinical, neuroradiological and genetic features of 19 Caucasian patients (aged 3-65 years) harbouring heterozygous KIF1A variants, and extensively review the available literature to improve current classification of KIF1A-related disorders. RESULTS: Patients were divided into two groups. Group 1 comprised patients with a complex phenotype with prominent pyramidal signs, variably associated in all but one case with additional features (ie, epilepsy, ataxia, peripheral neuropathy, optic nerve atrophy); conversely, patients in group 2 presented an early onset or congenital ataxic phenotype. Fourteen different heterozygous missense variants were detected by next-generation sequencing screening, including three novel variants, most falling within the kinesin motor domain. CONCLUSION: The present study further enlarges the clinical and mutational spectrum of KIF1A-related disorders by describing a large series of patients with dominantly inherited KIF1A pathogenic variants ranging from pure to complex forms of hereditary spastic paraparesis/paraplegias (HSP) and ataxic phenotypes in a lower proportion of cases. A comprehensive review of the literature indicates that KIF1A screening should be implemented in HSP regardless of its mode of inheritance or presentations as well as in other complex neurodegenerative or neurodevelopmental disorders showing congenital or early onset ataxia.


Subject(s)
Kinesins/genetics , Neurodegenerative Diseases/genetics , Neurodevelopmental Disorders/genetics , Adolescent , Adult , Aged , Ataxia/congenital , Ataxia/genetics , Child , Child, Preschool , Female , Heterozygote , Humans , Male , Middle Aged , Mutation , Retrospective Studies , Young Adult
12.
Int J Mol Sci ; 23(20)2022 Oct 18.
Article in English | MEDLINE | ID: mdl-36293304

ABSTRACT

Plasma small RNAs have been recently explored as biomarkers in Huntington's disease (HD). We performed an exploratory study on nine HD patients, eight healthy subjects (HS), and five psychiatric patients (PP; to control for iatrogenic confounder effects) through an Affymetrix-Gene-Chip-miRNA-Array. We validated the results in an independent population of 23 HD, 15 pre-HD, 24 PP, 28 Alzheimer's disease (AD) patients (to control the disease-specificity) and 22 HS through real-time PCR. The microarray results showed higher levels of U13 small nucleolar RNA (SNORD13) in HD patients than controls (fold change 1.54, p = 0.003 HD vs. HS, and 1.44, p = 0.0026 HD vs. PP). In the validation population, a significant increase emerged with respect to both pre-HD and the control groups (p < 0.0001). SNORD13 correlated with the status of the mutant huntingtin carrier (r = 0.73; p < 0.001) and the disease duration (r = 0.59; p = 0.003). The receiver operating characteristic (ROC) curve analysis showed the high accuracy of SNORD13 in discriminating HD patients from other groups (AUC = 0.963). An interactome and pathway analysis on SNORD13 revealed enrichments for factors relevant to HD pathogenesis. We report the unprecedented finding of a potential disease-specific role of SNORD13 in HD. It seems to peripherally report a 'tipping point' in the pathogenic cascade at the neuronal level.


Subject(s)
Huntington Disease , MicroRNAs , Humans , Huntington Disease/genetics , Huntington Disease/metabolism , RNA, Small Nucleolar/genetics , Pilot Projects , Huntingtin Protein/genetics , Biomarkers
13.
Int J Mol Sci ; 22(7)2021 Apr 02.
Article in English | MEDLINE | ID: mdl-33918133

ABSTRACT

Multiple sclerosis is a complex, multifactorial, dysimmune disease prevalent in women. Its etiopathogenesis is extremely intricate, since each risk factor behaves as a variable that is interconnected with others. In order to understand these interactions, sex must be considered as a determining element, either in a protective or pathological sense, and not as one of many variables. In particular, sex seems to highly influence immune response at chromosomal, epigenetic, and hormonal levels. Environmental and genetic risk factors cannot be considered without sex, since sex-based immunological differences deeply affect disease onset, course, and prognosis. Understanding the mechanisms underlying sex-based differences is necessary in order to develop a more effective and personalized therapeutic approach.


Subject(s)
Multiple Sclerosis/etiology , Sex Characteristics , Humans , Risk Factors
14.
Ann Neurol ; 85(2): 296-301, 2019 02.
Article in English | MEDLINE | ID: mdl-30549309

ABSTRACT

Easily accessible biomarkers in Huntington disease (HD) are actively searched. We investigated telomere length and DNA double-strand breaks (histone variant pγ-H2AX) as predictive disease biomarkers in peripheral blood mononuclear cells (PBMC) from 25 premanifest subjects, 58 HD patients with similar CAG expansion in the huntingtin gene (HTT), and 44 healthy controls (HC). PBMC from the pre-HD and HD groups showed shorter telomeres (p < 0.0001) and a significant increase of pγ-H2AX compared to the controls (p < 0.0001). The levels of pγ-H2AX correlated robustly with the presence of the mutated gene in pre-HD and HD. The availability of a potentially reversible biomarker (pγ-H2AX) in the premanifest stage of HD, negligible in HC, provides a novel tool to monitor premanifest subjects and find patient-specific drugs. Ann Neurol 2018;00:1-6 ANN NEUROL 2019;85:296-301.


Subject(s)
DNA Damage , Huntington Disease/metabolism , Prodromal Symptoms , Telomere/metabolism , Adult , Aged , Biomarkers/metabolism , Case-Control Studies , Female , Flow Cytometry , Histones/metabolism , Humans , Leukocytes, Mononuclear , Male , Middle Aged , Phosphorylation , Young Adult
15.
Opt Express ; 28(26): 38907-38916, 2020 Dec 21.
Article in English | MEDLINE | ID: mdl-33379449

ABSTRACT

We consider refractive index sensing with optical bounds states in the continuum (BICs) in dielectric gratings. Applying a perturbative approach we derived the differential sensitivity and the figure of merit of a sensor operating in the spectral vicinity of a BIC. Optimisation design approach for engineering an effective sensor is proposed. An analytic formula for the maximal sensitivity with an optical BIC is derived. The results are supplied with straightforward numerical simulations.

16.
Environ Microbiol ; 21(9): 3489-3504, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31106946

ABSTRACT

Several important bacterial characteristics, such as biological nitrogen fixation, phosphate solubilization, 1-aminocyclopropane-1-carboxylate deaminase activity and production of siderophores and phytohormones, can be assessed as plant growth promotion traits. Our aim was to evaluate the effects of nitrogen fixing and indole-3-acetic acid (IAA) producing endophytes in two Oryza sativa cultivars (Baldo and Vialone Nano). Three bacteria, Herbaspirillum huttiense RCA24, Enterobacter asburiae RCA23 and Staphylococcus sp. 377, producing different IAA levels, were tested for their ability to enhance nifH gene expression and nitrogenase activity in Enterobacter cloacae RCA25. Results showed that H. huttiense RCA24 performed best. Improvement in nitrogen fixation and changes in physiological parameters such as chlorophyll, nitrogen content and shoot dry weight were observed for plants co-inoculated with strains RCA25 and RCA24 in a 10:1 ratio. Based on confocal laser scanning microscopy analysis, strain RCA24 was the best colonizer of the root interior and the only IAA producer located in the same root niche occupied by RCA25 cells. This work shows that the choice of a bio-inoculum having the right composition is one of the key aspects to be considered for the inoculation of a specific host plant cultivar with microbial consortia.

17.
Opt Express ; 27(13): 18776-18786, 2019 Jun 24.
Article in English | MEDLINE | ID: mdl-31252814

ABSTRACT

In this work, we investigate the evanescent field sensing mechanism provided by an all-dielectric metasurface supporting bound states in the continuum (BICs). The metasurface is based on a transparent photonic crystal with subwavelength thickness. The BIC electromagnetic field is localized along the direction normal to the photonic crystal nanoscale-thin slab (PhCS) because of a topology-induced confinement, exponentially decaying in the material to detect. On the other hand, it is totally delocalized in the PhCS plane, which favors versatile and multiplexing sensing schemes. Liquids with different refractive indices, ranging from 1.33 to 1.45, are infiltrated in a microfluidic chamber bonded to the sensing dielectric metasurface. We observe an experimental exponential sensitivity leading to differential values as large as 226 nm/RIU with excellent FOM. This behavior is explained in terms of the physical superposition of the field with the material under investigation and supported by a thorough numerical analysis. The mechanism is then translated to the case of molecular adsorption where a suitable theoretical engineering of the optical structure points out potential sensitivities as large as 4000 nm/RIU.

19.
Mult Scler ; 23(3): 442-446, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27270497

ABSTRACT

BACKGROUND: Alterations of intestinal permeability (IP) may contribute to the pathophysiology of immune-mediated diseases. OBJECTIVE: We investigated the possible association between IP changes and multiple sclerosis (MS). METHODS: We studied 22 patients with relapsing-remitting multiple sclerosis (RRMS) and 18 age- and sex-matched healthy donors (HDs), including five twin pairs (one concordant, and four discordant for disease). Measurement of lactulose (L) and mannitol (M; two non-metabolized sugars) levels in urine samples, after an oral load, allowed to quantify gut dysfunction. RESULTS: The proportion of participants with increased IP was significantly higher in patients than in HDs (16/22 (73%) versus 5/18 (28%); p = 0.001). Accordingly, the L/M urinary ratio showed significantly higher values in patients than in controls ( p = 0.0284). Urinary mannitol concentration was significantly lower in patients than in controls ( p = 0.022), suggesting a deficit of absorption from intestinal lumen. Such changes did not appear related to patients' clinical-radiological features. CONCLUSION: The relatively high proportion of IP changes in RR-MS patients seems to confirm our work hypothesis and warrants more work to confirm the result on a larger sample, and to understand the implications for related immunological disturbances and intestinal microbiota alterations. Our finding may also have relevance for oral treatments, recently introduced in clinical practice.


Subject(s)
Gastrointestinal Microbiome/physiology , Lactulose/therapeutic use , Mannitol/therapeutic use , Multiple Sclerosis, Relapsing-Remitting/drug therapy , Adult , Female , Gastrointestinal Agents/therapeutic use , Gastrointestinal Microbiome/drug effects , Humans , Middle Aged , Permeability/drug effects , Pilot Projects
20.
Acta Paediatr ; 106(4): 619-626, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28090675

ABSTRACT

AIM: The effect of a supernumerary X chromosome on bones has not been reported, and this study evaluated bone mineral status and metabolism in nonmosaic triple X syndrome. METHODS: This cross-sectional study comprised 19 girls, with a median age of 10.9 years, with nonmosaic triple X syndrome and a control group matched for age and body size. We studied ionised and total calcium, phosphate, parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D, osteocalcin, bone alkaline phosphatase levels and urinary deoxypyridinoline concentrations. We also measured the phalangeal amplitude-dependent speed of sound (AD-SoS) and the bone transmission time (BTT) Z-scores. RESULTS: Patients with nonmosaic triple X syndrome showed significantly reduced AD-SoS (p < 0.005) and BTT Z-scores (p < 0.0001) compared to the control group, and these results persisted when we divided the sample into prepubertal and pubertal patients (p < 0.05). These patients also had significantly reduced ionised calcium (p < 0.005) and 25(OH)D levels (p < 0.005) and higher phosphate (p < 0.0001) and PTH (p < 0.0001) levels. CONCLUSION: Subjects with nonmosaic triple X syndrome exhibited a significant impairment in bone mineral status and metabolism similar to other X polisomy, such as Klinefelter's syndrome. This suggests the presence of a primary bone deficit and the need for regular and close monitoring of these subjects.


Subject(s)
Bone and Bones/metabolism , Calcification, Physiologic , Sex Chromosome Disorders of Sex Development/metabolism , Adolescent , Child , Chromosomes, Human, X/metabolism , Cross-Sectional Studies , Humans , Sex Chromosome Aberrations , Trisomy
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