The purpose of this article is to review coculture fermentations in industrial biotechnology. Examples for the advantageous utilization of cocultures instead of single cultivations include the ...production of bulk chemicals, enzymes, food additives, antimicrobial substances and microbial fuel cells. Coculture fermentations may result in increased yield, improved control of product qualities and the possibility of utilizing cheaper substrates. Cocultivation of different micro-organisms may also help to identify and develop new biotechnological substances. The relevance of coculture fermentations and the potential of improving existing processes as well as the production of new chemical compounds in industrial biotechnology are pointed out here by means of more than 35 examples.
Abstract
STUDY QUESTION
What is the accuracy of preimplantation genetic testing for aneuploidies (PGT-A) when considering human peri-implantation outcomes in vitro?
STUDY ANSWER
The probability of ...accurately diagnosing an embryo as abnormal was 100%, while the proportion of euploid embryos classified as clinically suitable was 61.9%, yet if structural and mosaic abnormalities were not considered accuracy increased to 100%, with a 0% false positive and false negative rate.
WHAT IS ALREADY KNOWN
Embryo aneuploidy is associated with implantation failure and early pregnancy loss. However, a proportion of blastocysts are mosaic, containing chromosomally distinct cell populations. Diagnosing chromosomal mosaicism remains a significant challenge for PGT-A. Although mosaic embryos may lead to healthy live births, they are also associated with poorer clinical outcomes. Moreover, the direct effects of mosaicism on early pregnancy remain unknown. Recently, developed in vitro systems allow extended embryo culture for up to 14 days providing a unique opportunity for modelling chromosomal instability during human peri-implantation development.
STUDY DESIGN, SIZE, DURATION
A total of 80 embryos were cultured to either 8 (n = 7) or 12 days post-fertilisation (dpf; n = 73). Of these, 54 were PGT-A blastocysts, donated to research following an abnormal (n = 37) or mosaic (n = 17) diagnosis. The remaining 26 were supernumerary blastocysts, obtained from standard assisted reproductive technology (ART) cycles. These embryos underwent trophectoderm (TE) biopsy prior to extended culture.
PARTICIPANTS/MATERIALS, SETTING, METHODS
We applied established culture protocols to generate embryo outgrowths. Outgrowth viability was assessed based on careful morphological evaluation. Nine outgrowths were further separated into two or more portions corresponding to inner cell mass (ICM) and TE-derived lineages. A total of 45 embryos were selected for next generation sequencing (NGS) at 8 or 12 dpf. We correlated TE biopsy profiles to both culture outcomes and the chromosomal status of the embryos during later development.
MAIN RESULTS AND THE ROLE OF CHANCE
Of the 73 embryos cultured to 12 dpf, 51% remained viable, while 49% detached between 8 and 12 dpf. Viable, Day 12 outgrowths were predominately generated from euploid blastocysts and those diagnosed with trisomies, duplications or mosaic aberrations. Conversely, monosomies, deletions and more complex chromosomal constitutions significantly impaired in vitro development to 12 dpf (10% vs. 77%, P < 0.0001). When compared to the original biopsy, we determined 100% concordance for uniform numerical aneuploidies, both in whole outgrowths and in the ICM and TE-derived outgrowth portions. However, uniform structural variants were not always confirmed later in development. Moreover, a high proportion of embryos originally diagnosed as mosaic remained viable at 12 dpf (58%). Of these, 71% were euploid, with normal profiles observed in both ICM and TE-derived lineages. Based on our validation data, we determine a 0% false negative and 18.5% false positive error rate when diagnosing mosaicism. Overall, our findings demonstrate a diagnostic accuracy of 80% in the context of PGT-A. Nevertheless, if structural and mosaic abnormalities are not considered, accuracy increases to 100%, with a 0% false positive and false negative rate.
LIMITATIONS REASONS FOR CAUTION
The inherent limitations of extended in vitro culture, particularly when modelling critical developmental milestones, warrant careful interpretation.
WIDER IMPLICATIONS OF THE FINDINGS
Our findings echo current prenatal testing data and support the high clinical predictive value of PGT-A for diagnosing uniform numerical aneuploidies, as well as euploid chromosomal constitutions. However, distinguishing technical bias from biological variability will remain a challenge, inherently limiting the accuracy of a single TE biopsy for diagnosing mosaicism.
STUDY FUNDING, COMPETING INTEREST(S)
This research is funded by the Ghent University Special Research Fund (BOF01D08114) awarded to M.P., the Research Foundation-Flanders (FWO.KAN.0005.01) research grant awarded to B.H. and De Snoo-van't Hoogerhuijs Stichting awarded to S.M.C.d.S.L. We thank Ferring Pharmaceuticals (Aalst, Belgium) for their unrestricted educational grant. The authors declare no competing interests.
TRIAL REGISTRATION NUMBER
N/A.
Abstract
STUDY QUESTION
To what extent does a trophectoderm (TE) biopsy reliably reflect the chromosomal constitution of the inner cell mass (ICM) in human blastocysts?
SUMMARY ANSWER
Concordance ...between TE and ICM was established in 62.1% of the embryos analysed.
WHAT IS KNOWN ALREADY
Next generation sequencing (NGS) platforms have recently been optimised for preimplantation genetic testing for aneuploidies (PGT-A). However, higher sensitivity has led to an increase in reports of chromosomal mosaicism within a single TE biopsy. This has raised substantial controversy surrounding the prevalence of mosaicism in human blastocysts and the clinical implications of heterogeneity between the TE and ICM.
STUDY DESIGN, SIZE, DURATION
To define the distribution and rate of mosaicism in human blastocysts, we assessed chromosomal profiles of the ICM and multiple TE portions obtained from the same embryo. We evaluated donated embryos with an unknown chromosomal profile (n = 34), as well as PGT-A blastocysts, previously diagnosed as abnormal or mosaic (n = 24). Our intra-embryo comparison included a total of 232 samples, obtained from 58 embryos.
PARTICIPANTS/MATERIALS, SETTING, METHODS
Four embryo samples, including the ICM and three distinct TE portions, were acquired from good quality blastocysts by micromanipulation. Whole genome amplification (WGA), followed by NGS was performed on all embryo segments. Profiles were compared between samples from the same embryo, while the results from pretested blastocysts were further correlated to the original report. The embryos investigated in our untested group were obtained from good prognosis patients (n = 25), with maternal age ranging from 23 to 39 years. For the pretested embryo group, maternal age ranged from 23 to 40 years (n = 18).
MAIN RESULTS AND THE ROLE OF CHANCE
We uncover chromosomal mosaicism, involving both numerical and structural aberrations, in up to 37.9% of the blastocysts analysed. Within the untested group, the overall concordance between the ICM and all TE portions was 55.9%. A normal ICM was detected in 20.6% of blastocysts for which at least one TE portion showed a chromosomal aberration. Conversely, 17.6% of embryos presented with mosaic or uniform abnormalities within the ICM, while showing normal or mosaic TE profiles. For the pretested blastocysts, the overall concordance between the ICM and all TE samples was 70.8%. However, 50% of embryos previously diagnosed with mosaicism did not confirm the original diagnosis. Notably, 31.3% of embryos with a mosaic aberration reported in the original TE biopsy, revealed a euploid profile in the ICM and all three TE samples. Taken together, concordance between the ICM and all TE portions was established in 62.1% of blastocysts, across both embryo groups. Finally, we could not observe a significant effect of age on embryo mosaicism (P = 0.101 untested group; P = 0.7309 pretested group). Similarly, ICM and TE quality were not found to affect the occurrence of chromosomal mosaicism (P = 0.718 and P = 0.462 untested group; P = 1.000 and P = 0.2885 pretested group).
LARGE SCALE DATA
All data that support the findings of this study are available online in Vivar (http://cmgg.be/vivar) upon request.
LIMITATIONS, REASONS FOR CAUTION
Evaluating biological variation in some instances remains challenging. The technological limitations of sampling mitotic errors that lead to mosaicism, as well as WGA artefacts, warrant careful interpretation.
WIDER IMPLICATIONS OF THE FINDINGS
Our results highlight the complex nature of genetic (in)stability during early ontogenesis and indicate that blastocysts harbour a higher rate of chromosomal mosaicism than may have been anticipated. Moreover, our findings reveal an overall high diagnostic sensitivity and relatively low specificity in the context of PGT-A. This suggests that a considerable proportion of embryos are potentially being classified as clinically unsuitable. Ultimately, more precise quantification will benefit the clinical management of embryo mosaicism.
STUDY FUNDING/COMPETING INTEREST(S)
M.P. is supported by the Special Research Fund, Bijzonder Onderzoeksfonds (BOF01D08114). J.T. and L.D. are supported by the agency for innovation through science (131673, 141441). B.H. and this research are supported by the Special Research Fund, Bijzonder Onderzoeksfonds (BOF15/GOA/011). The authors declare no competing interests.
TRIAL REGISTRATION NUMBER
Not applicable.
Microinvasive glaucoma surgery: A review of 3476 eyes Nichani, Prem; Popovic, Marko M.; Schlenker, Matthew B. ...
Survey of ophthalmology,
September-October 2021, 2021 Sep-Oct, 2021-09-00, 20210901, Letnik:
66, Številka:
5
Journal Article
Recenzirano
Microinvasive glaucoma surgery (MIGS) is a potentially safer and more efficacious method studied in patients with mild-to-moderate open-angle glaucoma requiring less invasive treatment goals; ...however, the literature on MIGS must be thoroughly evaluated. We conducted a review of MIGS by searching MEDLINE, EMBASE, and Cochrane CENTRAL. Primary efficacy indicators were reductions in intraocular pressure and topical medication use postoperatively. While all comparative randomized controlled trials assessing MIGS in English peer-reviewed journals were included, only observational studies with a target follow-up of at least one year and a high priority score were analyzed, resulting in a total of 3476 eyes across 20 trials. The mean age was 69.5 ± 2.9 years, 53.7% were female, and 77.4% were Caucasian. One study had last follow-up at less than one year, fifteen studies had follow-up extending 1-2 years, and four had longer than two years of follow-up. A pattern of more significant intraocular pressure and medication reduction was observed in patients who underwent MIGS (n = 2170) relative to control (n = 1306) interventions. iStent had the most literature supporting its efficacy, followed by Hydrus. The most common adverse events after MIGS implantation included stent obstruction, inflammation, and subsequent surgical intervention. Surgical complication rates and efficacy are favorable after MIGS. This review helps to consolidate the high-quality evidence that exists for various MIGS procedures and to identify gaps where further research is needed.
A general construction of a particular class of zero correlation zone sequences is proposed. The general construction produces the sets of so-called interference-free zero autocorrelation zone ...(IF-ZAZ) sequences, where any two sequences from a set have all-zero periodic cross correlation, while each sequence has periodic autocorrelation equal to zero in multiple zones of non-zero delays. The length D of each such ZAZ has the maximum possible value <inline-formula> <tex-math notation="LaTeX">D=t-1 </tex-math></inline-formula> for given sequence length <inline-formula> <tex-math notation="LaTeX">N = tm </tex-math></inline-formula> and for the given number of sequences in the set <inline-formula> <tex-math notation="LaTeX">M = m </tex-math></inline-formula>. As an important special case of the general construction, we present the construction of generalized chirp-like IF-ZAZ sequences that allow particularly simple implementation of the corresponding banks of matched filters.
The paper reports the study on dielectric functions of TiN films implanted with Ag ions and after annealing at 400 °C and 700 °C, employing spectroscopic ellipsometry technique. By using ...Drude-Lorentz modelling we have analysed and discussed in detail the evolution of screened and unscreened plasma frequency as well as Drude parameter. In comparison to as deposited film the real part of dielectric constant for Ag-implanted layers exhibits less negative values with increasing ion fluence implying the films possess less metallicity, whereas after annealing TiN becomes more metallic. Simultaneously, after implantation, the imaginary part is more than an order of magnitude lower than for the as deposited TiN and several times lower than that of Au and Ag. The magnitude of imaginary contribution of Ag-implanted TiN films decreases further after subsequent heat treatment at both 400 °C and 700 °C annealing temperatures. Although the differences in stoichiometry and microstructural changes, such as crystallite size, concentration of grain boundaries and defect density were assumed to be the major reason for the variation in optical properties of TiN, spectroscopic ellipsometry data exhibited much stronger effects than expected and indicated some other mechanisms could also be responsible for such behaviour.
Display omitted
•Optical properties of plasmonic TiN thin films were investigated.•TiN was modified by Ag implantation and post-thermal annealing at 400 °C or 700 °C.•Implantation of Ag have a direct consequence on the optical losses of TiN.•After annealing the films exhibit losses lower than those of pure Au and Ag.•Low losses originate from the high values of the Drude broadening parameter.
Mediation analysis aims at estimating to what extent the effect of an exposure on an outcome is explained by a set of mediators on the causal pathway between the exposure and the outcome. The total ...effect of the exposure on the outcome can be decomposed into an indirect effect, i.e. the effect explained by the mediators jointly, and a direct effect, i.e. the effect unexplained by the mediators. However finer decompositions are possible in presence of independent or sequential mediators.
We review four statistical methods to analyse multiple sequential mediators, the inverse odds ratio weighting approach, the inverse probability weighting approach, the imputation approach and the extended imputation approach. These approaches are compared and implemented using a case-study with the aim to investigate the mediating role of adverse reproductive outcomes and infant respiratory infections in the effect of maternal pregnancy mental health on infant wheezing in the Ninfea birth cohort.
Using the inverse odds ratio weighting approach, the direct effect of maternal depression or anxiety in pregnancy is equal to a 59% (95% CI: 27%,94%) increased prevalence of infant wheezing and the mediated effect through adverse reproductive outcomes is equal to a 3% (95% CI: -6%,12%) increased prevalence of infant wheezing. When including infant lower respiratory infections in the mediation pathway, the direct effect decreases to 57% (95% CI: 25%,92%) and the indirect effect increases to 5% (95% CI: -5%,15%). The estimates of the effects obtained using the weighting and the imputation approaches are similar. The extended imputation approach suggests that the small joint indirect effect through adverse reproductive outcomes and lower respiratory infections is due entirely to the contribution of infant lower respiratory infections, and not to an increased prevalence of adverse reproductive outcomes.
The four methods revealed similar results of small mediating role of adverse reproductive outcomes and early respiratory tract infections in the effect of maternal pregnancy mental health on infant wheezing. The choice of the method depends on what is the effect of main interest, the type of the variables involved in the analysis (binary, categorical, count or continuous) and the confidence in specifying the models for the exposure, the mediators and the outcome.
Ultra-reliable short-packet communication is a major challenge in future wireless networks with critical applications. To achieve ultra-reliable communications beyond 99.999%, this paper envisions a ...new interaction-based communication paradigm that exploits feedback from the receiver. We present AttentionCode, a new class of feedback codes leveraging deep learning (DL) technologies. The underpinnings of AttentionCode are three architectural innovations: AttentionNet, input restructuring, and adaptation to fading channels, accompanied by several training methods, including large-batch training, distributed learning, look-ahead optimizer, training-test signal-to-noise ratio (SNR) mismatch, and curriculum learning. The training methods can potentially be generalized to other wireless communication applications with machine learning. Numerical experiments verify that AttentionCode establishes a new state of the art among all DL-based feedback codes in both additive white Gaussian noise (AWGN) channels and fading channels. In AWGN channels with noiseless feedback, for example, AttentionCode achieves a block error rate (BLER) of 10−7 when the forward channel SNR is 0 dB for a block size of 50 bits, demonstrating the potential of AttentionCode to provide ultra-reliable short-packet communications.
Fosfomycin: an old, new friend Popovic, M; Steinort, D; Pillai, S ...
European journal of clinical microbiology & infectious diseases,
02/2010, Letnik:
29, Številka:
2
Journal Article
Recenzirano
Fosfomycin (FOM) is an antibiotic which has varying application indications across the globe. European, Japanese, South African and Brazilian usage practices are much broader, involving multiple ...formulations of FOM than the currently limited application of FOM in the United States, where uncomplicated urinary tract infection represents the only indication for FOM-tromethamine. Based on early difficulty in determining FOMs genuine in vitro activity, there was initial skepticism about its efficacy and application range. However, in the mid 1970s, correctly executed experiments coupled with an improved understanding of microbiological concepts opened the door for broader use of FOM. During the following 40 years FOM was evaluated in pre-clinical and clinical trials in a wide range of applications and in a multitude of settings. The gathering of pharmacokinetic and pharmacodynamic data was incorporated into large scale studies in which FOM efficacy was further explored and proven. Among European nations, intravenous FOM-disodium for patients presenting with soft tissue infections, sepsis or deep seated infectious processes has become well accepted over the last two decades. The recent emergence of bacterial strains, which impede and encumber pharmacotherapy, namely, MRSA, ESBL and MSSA, lends itself to the idea of reviving long-standing, sensibly used antimicrobial agents like FOM. This review provides a comprehensive conspectus on FOM's history, mode of action, tissue penetration characteristics, resistance, antibacterial activity, combination partners and clinical uses among other facets of interest.
The present paper investigates the effects of thermal annealing on the structural and magnetic properties of Co thin films. The films were prepared by using electron-beam evaporation method onto Si ...(100) wafers and annealed in vacuum at 200 °C, 300 °C and 400 °C. A combination of X-ray diffraction, Rutherford backscattering spectrometry, X-ray photoelectron spectroscopy, transmission electron microscopy and energy-dispersive X-ray spectrometry were used to characterize structural properties and the composition of the films, while magnetic behavior was studied by magneto-optical Kerr effect measurements. It was found that as deposited Co layer show predominantly uniaxial magnetic anisotropy, while after annealing at 200 °C and 300 °C a strong influence of fourfold contribution is observed, which is assigned to the thermally induced HCP→FCC phase transition. With further increase in annealing temperature of 400 °C the isotropic contribution becomes the main component of magnetization. Besides, a strong variation in coercive field with annealing temperature was observed, where the coercivity seems to depend closely on the crystallite size. The highest value of HC equals ∼70 Oe and was found for the temperature of 400 °C, where also mixing at the interface has started and formation of CoSi was observed.
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●E-beam evaporated Co thin films were annealed at 200 °C, 300 °C and 400 °C in vacuum.●At 200 °C and 300 °C HCP→FCC phase transition induces four-fold magnetic anisotropy.●Beyond 300 °C cobalt thin films exhibit isotropic magnetization.●Coercivity of Co films depend closely on the crystallite size.●At 400 °C intermixing has started and formation of thin CoSi layer was observed.
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