Chemical and Physicochemical Pretreatment of Lignocellulosic Biomass: A Review

Overcoming the recalcitrance (resistance of plant cell walls to deconstruction) of lignocellulosic biomass is a key step in the production of fuels and chemicals. The recalcitrance is due to the highly crystalline structure of cellulose which is embedded in a matrix of polymers-lignin and hemicellulose. The main goal of pretreatment is to overcome this recalcitrance, to separate the cellulose from the matrix polymers, and to make it more accessible for enzymatic hydrolysis. Reports have shown that pretreatment can improve sugar yields to higher than 90% theoretical yield for biomass such as wood, grasses, and corn. This paper reviews different leading pretreatment technologies along with their latest developments and highlights their advantages and disadvantages with respect to subsequent hydrolysis and fermentation. The effects of different technologies on the components of biomass (cellulose, hemicellulose, and lignin) are also reviewed with a focus on how the treatment greatly enhances enzymatic cellulose digestibility

The burden of prostate cancer in Trinidad and Tobago: one of the highest mortality rates in the world

Purpose In Trinidad and Tobago (TT), prostate cancer (CaP) is the most commonly diagnosed malignancy and the leading cause of cancer deaths among men. TT currently has one of the highest CaP mortality rates in the world. Methods: 6,064 incident and 3,704 mortality cases of CaP occurring in TT from January 1995 to 31 December 2009 reported to the Dr. Elizabeth Quamina Cancer population-based cancer registry for TT, were analyzed to examine CaP survival, incidence, and mortality rates and trends by ancestry and geography. Results: The age-standardized CaP incidence and mortality rates (per 100,000) based on the 1960 world-standardized in 2009 were 64.2 and 47.1 per 100,000. The mortality rate in TT increased between 1995 (37.9 per 100,000) and 2009 (79.4 per 100,000), while the rate in the US decreased from 37.3 per 100,000 to 22.1 per 100,000 over the same period. Fewer African ancestry patients received treatment relative to those of Indian and mixed ancestry (45.7%, 60.3%, and 60.9%, respectively). Conclusions: Notwithstanding the limitations surrounding data quality, our findings highlight the increasing burden of CaP in TT and the need for improved surveillance and standard of care. Our findings highlight the need for optimized models to project cancer rates in developing countries like TT. This study also provides the rationale for targeted screening and optimized treatment for CaP to ameliorate the rates we report. Electronic supplementary material The online version of this article (10.1007/s10552-018-1038-8) contains supplementary material, which is available to authorized users

Guiding principles for the responsible development of artificial intelligence tools for healthcare.

Several principles have been proposed to improve use of artificial intelligence (AI) in healthcare, but the need for AI to improve longstanding healthcare challenges has not been sufficiently emphasized. We propose that AI should be designed to alleviate health disparities, report clinically meaningful outcomes, reduce overdiagnosis and overtreatment, have high healthcare value, consider biographical drivers of health, be easily tailored to the local population, promote a learning healthcare system, and facilitate shared decision-making. These principles are illustrated by examples from breast cancer research and we provide questions that can be used by AI developers when applying each principle to their work

Xenin is a novel anorexigen in goldfish (Carassius auratus).

Xenin, a highly conserved 25 amino acid peptide cleaved from the N-terminus of the coatomer protein alpha (COPA), is emerging as a food intake regulator in mammals and birds. To date, no research has been conducted on xenin biology in fish. This study aims to identify the copa mRNA encoding xenin in goldfish (Carassius auratus) as a model, to elucidate its regulation by feeding, and to describe the role of xenin on appetite. First, a partial sequence of copa cDNA, a region encoding xenin, was identified from goldfish brain. This sequence is highly conserved among both vertebrates and invertebrates. RT-qPCR revealed that copa mRNAs are widely distributed in goldfish tissues, with the highest levels detected in the brain, gill, pituitary and J-loop. Immunohistochemistry confirmed also the presence of COPA peptide in the hypothalamus and enteroendocrine cells on the J-loop mucosa. In line with its anorexigenic effects, we found important periprandial fluctuations in copa mRNA expression in the hypothalamus, which were mainly characterized by a gradually decrease in copa mRNA levels as the feeding time was approached, and a gradual increase after feeding. Additionally, fasting differently modulated the expression of copa mRNA in a tissue-dependent manner. Peripheral and central injections of xenin reduce food intake in goldfish. This research provides the first report of xenin in fish, and shows that this peptide is a novel anorexigen in goldfish

Xenin is a novel anorexigen in goldfish (<i>Carassius auratus</i>)

<div><p>Xenin, a highly conserved 25 amino acid peptide cleaved from the N-terminus of the coatomer protein alpha (COPA), is emerging as a food intake regulator in mammals and birds. To date, no research has been conducted on xenin biology in fish. This study aims to identify the <i>copa</i> mRNA encoding xenin in goldfish (<i>Carassius auratus</i>) as a model, to elucidate its regulation by feeding, and to describe the role of xenin on appetite. First, a partial sequence of <i>copa</i> cDNA, a region encoding xenin, was identified from goldfish brain. This sequence is highly conserved among both vertebrates and invertebrates. RT-qPCR revealed that <i>copa</i> mRNAs are widely distributed in goldfish tissues, with the highest levels detected in the brain, gill, pituitary and J-loop. Immunohistochemistry confirmed also the presence of COPA peptide in the hypothalamus and enteroendocrine cells on the J-loop mucosa. In line with its anorexigenic effects, we found important periprandial fluctuations in <i>copa</i> mRNA expression in the hypothalamus, which were mainly characterized by a gradually decrease in <i>copa</i> mRNA levels as the feeding time was approached, and a gradual increase after feeding. Additionally, fasting differently modulated the expression of <i>copa</i> mRNA in a tissue-dependent manner. Peripheral and central injections of xenin reduce food intake in goldfish. This research provides the first report of xenin in fish, and shows that this peptide is a novel anorexigen in goldfish.</p></div

Pre- and post-prandial changes of <i>copa</i> mRNA expression in the goldfish hypothalamus (A), J-loop (B), and liver (C).

<p>The mRNA expression of <i>copa</i> was normalized to <i>β-actin</i> and represented relative to the -3 h scheduled feeding group. Data are presented as mean + SEM (n = 4 fish). Columns sharing a same letter are not statistically different (p < 0.05, one-way ANOVA and Student-Newman-Keuls tests).</p

Fasting-induced changes of <i>copa</i> mRNA expression in goldfish central and peripheral tissues.

<p>(<b>A–C</b>) Expression of <i>copa</i> mRNAs after a 3-day fasting period in the goldfish hypothalamus (A), J-loop (C), and liver (E). The mRNA expression of <i>copa</i> was normalized to <i>β-actin</i> and represented relative to the unfed group. Data are presented as mean + SEM (n = 4 fish). Columns with a different letter are statistically different (p < 0.05, t-test). (<b>D–F</b>) Expression of <i>copa</i> mRNAs after a 7-day fasting period and refeeding in the goldfish hypothalamus (D), J-loop (E), and liver (F). The mRNA expression of <i>copa</i> was normalized to <i>β-actin</i> and represented relative to the unfed group. Data are presented as mean + SEM (n = 4 fish). Columns with a different letter are statistically different (p < 0.05, one-way ANOVA and Student-Newman-Keuls tests).</p

Xenin-like immunoreactivity in the goldfish brain.

<p>(<b>A</b>) Sagittal view of a goldfish brain stained with DAPI (blue). Arrows indicate the region of the posterior periventricular nucleus (NPP<i>v</i>), nucleus anterior tuberis (NAT), and posterior nucleus lateralis tuberis (NLT<i>p</i>). Scale bar = 500 μm. (<b>B–D</b>) Immunohistochemical staining of goldfish NAT, NLT<i>p</i> and NPP<i>v</i> neurons for xenin-like immunoreactivity (red). All images are merged with DAPI showing nuclei in blue. Arrows point to immunopositive cells. In C, open arrows point to xenin-like immunoreactive neurons along the ventricle, and closed arrows to positive neurons lateral to the ventricle. Scale bars = 50 μm (B), 100 μm (C, D), 20 μm (inset in D). (<b>E</b>) Image of a negative control slide stained with secondary antibody alone. Scale bar = 50 μm. (<b>F, G</b>) Transversal representative sections of goldfish brain treated with specific primary anti-xenin antibody pre-absorbed in xenin. Scale bars = 200 μm.</p

Phylogenetic analysis of the partial COPA sequence obtained from goldfish.

<p><b>(A)</b> Phylogenetic tree showing the evolutionary relationships of the obtained nucleotide sequence of goldfish <i>copa</i> with those of other species. Tree was inferred by the neighbor-joining method using the online tool <a href="http://www.phylogeny.fr" target="_blank">www.phylogeny.fr</a>. The scale bar indicates the average number of substitutions per position (a relative measure of evolutionary distance). The names of the species used for the alignment are provided in the figure. GenBank accession numbers of the sequences used are as follows: <i>Bombyx mori</i>, NM_001172721.1; <i>Bos taurus</i>, NM_001105645.1; <i>Carassius auratus</i>, JQ929912.1; <i>Cavia porcellus</i>, XM_003466569.3; <i>Ciona intestinalis</i>, XM_002131228.4; <i>Cricetulus griseus</i>, XM_007629307.2; <i>Danio rerio</i>, NM_001001941.2; <i>Equus caballus</i>, XM_023640888.1; <i>Gallus gallus</i>, NM_001031405.2; <i>Homo sapiens</i>, NM_001098398.1; <i>Loxodonta africana</i>, XM_023554162.1; <i>Macaca mulatta</i>, XM_015113467.1; <i>Meleagris gallopavo</i>, XM_003213951.3; <i>Monodelphis domestica</i>, XM_016430274.1; <i>Mus musculus</i>, NM_009938.4; <i>Nomascus leucogenys</i>, XM_012510889.1; <i>Pan troglodytes</i>, XM_001171563.4; <i>Rattus norvegicus</i>, NM_001134540.1; <i>Saccoglossus kowalevskii</i>, XM_002731243.2; <i>Salmo salar</i>, XM_014140665.1; <i>Sus scrofa</i>, XM_001928697.6; <i>Thalassiosira pseudonana</i>, XM_002291058.1; <i>Xenopus laevis</i>, NM_001093019.2; <i>Xenopus tropicalis</i>, NM_001127994.1. <b>(B)</b> Alignment of the first 61 aa of COPA from an algal species, invertebrate species, teleost fishes, amphibians, avians, and mammals. The species names are provided on the left-hand side of the alignment and the number of aa is present on the right-hand side of the alignment. The coloured aa highlights the differences in conservation between species. The first 25 aa (which correspond to the xenin region) are boxed.</p

Effects of IP (A) and ICV (B) administration of xenin on food intake.

<p>Data are presented as mean + SEM (n = 6 fish for IP, 4 fish for ICV). Columns with a different letter are statistically different (p < 0.05, one-way ANOVA and Student-Newman-Keuls tests).</p