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The present study evaluates the toxicity of AgNPs synthesised from Padina tetrastromatica (P-AgNPs) through Brine Shrimp Lethality Assay. The aqueous Padina seaweed extract was treated with AgNO3 to synthesise P-AgNPs, and these NPs were then characterised by multiple analytical techniques. The UV-Vis spectra displayed characteristic SPR peaks of AgNPs at about 409.5 nm. The TEM and particle size distribution results verified the formation of polydisperse spherical P-AgNPs with a dominant size of around 48 nm. Zeta potential analysis indicates the moderate stability of P-AgNPs. The FTIR spectrum of P-AgNPs reveals the presence of organic functional groups, suggesting the involvements of seaweed organic matters in capping and stabilising AgNPs. Though the 24-h mortality test showed a dose-dependent increase in Artemia death, the results imply a non-toxic property in P-AgNPs (LC50 value: 4300 mg/L; >1000 mg/L). These findings conclusively suggest the acute exposure to P-AgNPs has no substantial risk to marine organisms.

Temperature-responsive resistance transition behaviors of the melamine sponges wrapped with different graphene oxide derivatives (i.e. nanoribbon, wide-ribbon and sheet) were investigated. Melamine sponge composites coated by three types of GO derivatives were prepared by a simple dip-coating approach. All these composites show good mechanical flexibility and reliability (almost unchanged compressive stress at 70 % strain after 100 cycles), high hydrophobicity (water contact angle >120°), excellent flame resistance (self-extinguishing) and structural stability even after burning, which was used to construct the resistance-based fire alarm/warning sensor. Notably, the different resistance response behaviors of such sensors are strongly dependent on the GO size and network formed on the MF skeleton surface. Typically, at a fixed high temperature of ∼350 ℃, the three fire alarm sensors show different response time (to trigger the alarm light) of 6.3, 8.4 and 11.1 s for nanoribbon, wide-ribbon and sheet at the same concentration, respectively. The structural observation and chemical analysis demonstrated that the discrepancy of temperature-responsive resistance transition behaviors of various GO derivatives was strongly determined by their different thermal reduction degrees during the high-temperature or flame treating process. This work offers a design and development for construction of smart fire alarm device for potential fire prevention and safety applications.

Low anterior resection syndrome (LARS) is a common postoperative complication in patients with colorectal cancer, which seriously affects their postoperative quality of life. At present, the aetiology of LARS is still unclear, but some risk factors have been studied. Accurate prediction and early management of medical intervention are keys to improving the quality of life of such high-risk patients.Based on machine-learning methods, this study used the follow-up results of postoperative patients with colorectal cancer to develop prediction models for LARS and conducted a comparative analysis between the different models.A total of 382 patients diagnosed with colorectal cancer and undergoing surgery at West China Hospital from April 2017 to December 2020 were retrospectively selected as the development cohort. Logistic regression, support vector machine, decision tree, random forest and artificial neural network algorithms were used to construct the prediction models of the obtained dataset. The models were internally validated using cross-validation. The area under the curve and Brier score measures were used to evaluate and compare the differentiation and calibration degrees of the models. The sensitivity, specificity, positive predictive value and negative predictive value of the different models were described for clinical use.A total of 342 patients were included, the incidence of LARS being 47.4% (162/342) during the six-month follow-up. After feature selection, the factors influencing the occurrence of LARS were found to be location, distance, diverting stoma, exsufflation and surgical type. The prediction models based on five machine-learning methods all showed acceptable performance.The five models developed based on the machine-learning methods showed good prediction performance. However, considering the simplicity of clinical use of the model results, the logistic regression model is most recommended. The clinical applicability of these models will also need to be evaluated with external cohort data.

Tantalum nitrides (TaN) have attracted much attention as a new material of energy exchangers in insensitive detonators, we mainly investigate its ignition law in this paper. Firstly, the paper utilizes numerical simulation to predict the influence of the substrate material, bridge zone thickness, bridge zone length and width on the ignition action. Then its reliability was verified by experiments, which provided technical support for the design of passivated pyrotechnics.

A family of fully sandwiched arachno-lanthanacarborane complexes formulated as {6-[µ-1,2-[o-C6H4(CH2)2]-1,2-C2B10H10]2Ln}{Li5(THF)10} (Ln = Tb, Dy, Ho, Er, Y) is successfully synthesized, where the “carbons-adjacent” carboranyl ligand (arachno-C2B10H104−) bears four negative charges and coordinates to the central lanthanide ions using the hexagonal 6­C2B4 face. Thus, the central lanthanide cations are pseudo-twelve-coordinate and have an approximate local D6h symmetry or hexagonal-prismatic geometry. As the crystal field effect imparted by this geometry is still unknown, we thoroughly investigated the magnetic properties of this series of complexes and found the crystal field imposed by this ligand causes a relation of Tb > Dy > Ho > Er for the energy gaps between the ground and the first excited states, which is of striking resemblance to the ferrocenophane and phthalocyanine ligands despite that the latter two ligands give disparate local coordination geometries. Moreover, the effective energy barrier to magnetization reversal of 445(10) K, observable hysteresis loop up to 4K and the relaxation time of the yttrium diluted sample reaching 193(17) seconds at 2 K under an optimized field for the Tb analogue of this family of arachno-lanthanacarborane complexes, render a new benchmark for Tb3+ based single-molecule magnets.

PurposeTraditional Malaysian vegetables, also known as ulam, are believed to have healing properties among the local community. Ulam is commonly reported to have high antioxidant content which makes it a popular food. The purpose of this paper is to determine the teratogenic potential of eight ulam, using zebrafish model. The tested ulam were Cosmos caudatus, Gynura procumbens, Labisia pumila var. alata, Phaleria macrocarpa, Polygonum minus, Piper sarmentosum, Premna foetida and Sauropus androgynous.Design/methodology/approachMethanol extract of ulam was prepared using the maceration method. Various concentrations of extracts were tested against fish embryo short-term toxicity test. The lethal concentration (LC50) and teratogenic effect of the ulam were determined.FindingsAmong all tested species, L. pumila, P. foetida and S. androgynous showed 100% lethal effect towards zebrafish embryos at concentrations of 10 µg/mL, 1,000 µg/mL and 100 µg/mL, respectively. The three ulam have exhibited teratogenic effect on zebrafish embryos after 72 h post-fertilization. L. pumila had induced yolk sac edema at 1.0 µg/mL for normalized measurement of 108.3 ± 2.0% (which is higher than negative control, p P. foetida had induced pericardial edema at 100 µg/mL for normalized measurement of 124.0 ± 4.6% (which is higher than negative control, p S. androgynus induced curve trunk at 30 µg/mL for the presence of 70.9 ± 4.2%.Originality/valueThe teratogenic effect of L. pumila, P. foetida and S. androgynous suggests the possible disruption in the embryogenesis in zebrafish, namely Notch, vascular endothelial growth factor (VEGF) and retinoic acid pathways. The results of ulam gave possible implications and insights on the cancer pathways involved, which could be a useful target for cancer research. This is the first report on teratogenicity evaluation of Malaysian ulam showing relationship to cancer pathways by using zebrafish embryo model.

PurposeThe purpose of this paper is to evaluate the antioxidant activity and toxicity of Clinacanthus nutans leaves from three conventional extraction methods, i.e. maceration, Soxhlet and magnetic stirring.Design/methodology/approachTotal flavonoid content (TFC) and phenolic content (TPC) were determined using colorimetric method of aluminum chloride and Folin-Ciocalteu (FC) assay, respectively. Antioxidant property of C. nutans was evaluated using 2,2'-diphenyl-1-pierylhydrazyl (DPPH) free radical scavenging assay. Cytotoxic activity of C. nutans against brine shrimp was evaluated based on LC50 (lethality concentration) after 24 h exposure to the plant extract.FindingsThe highest TPC of C. nutans was observed with Soxhlet extraction method (98.87 ± 10.43 mg of gallic acid equivalents (GAE/g) followed by maceration (68.77 ± 2.45 mg of GAE/g) and magnetic stirring (46.75 ± 2.45 mg of GAE/g). Interestingly, remarkable highest TFC was observed with magnetic stirring (568.90 ± 4.85 mg of rutin equivalent (RE)/g) followed by maceration (249.60 ± 2.79 mg of RE/g) and Soxhlet (174.8 ± 1.74 mg of RE/g). On the other hands, the extract obtained using maceration method showed the highest antioxidant activity (IC50: 14.18 mg/mL compared to ascorbic acid 144.36 µg/mL). Cytotoxicity of C. nutans from all extraction methods showed similar LC50 values with maceration (3.81 mg/mL), Soxhlet (2.61 mg/mL) and magnetic stirring (4.56 mg/mL), respectively.Originality/valueBoth phenolic and flavonoids are responsible for the antioxidant activity, of C. nutans extracts. Based on Meyer's toxicity index, all extracts were nontoxic (LC50>1 mg/mL).

Summary Design criteria for dysprosium(III) single-molecule magnets (SMMs) with large thermal energy barriers to magnetic reversal have been established and proven, and the challenge to enhance performance is in understanding and controlling electron-vibration coupling that is the origin of magnetic reversal. We have prepared an SMM, [Dy(L)2(py)5][BPh4] 1 (HL = (S)-(-)-1-phenylethanol), based on the archetype [Dy(OtBu)2(py)5][BPh4] 2. Compounds 1 and 2 have similarly large energy barriers of Ueff = 1,130(20) cm−1 and Ueff = 1,250(10) cm−1, and yet 1 shows magnetic hysteresis at a far higher temperature of 22 K cf. TH = 4 K for 2. Ab initio calculation of the electron-vibration coupling and spin dynamics shows that substitution of the alkoxide ligand in fact enhances relaxation over the energy barrier for 1 compared with 2, in agreement with experiment, and that the higher temperature of magnetic hysteresis likely owes to reduced quantum tunneling at low temperatures.

The dicarbollide ion, nido-C2 B9 H11 2- is isoelectronic with cyclopentadienyl. Herein, we make dysprosiacarboranes, namely [(C2 B9 H11 )2 Ln(THF)2 ][Na(THF)5 ] (Ln=Dy, 1Dy) and [(THF)3 (μ-H)3 Li]2 [{η5 -C6 H4 (CH2 )2 C2 B9 H9 }Dy{η2 :η5 -C6 H4 (CH2 )2 C2 B9 H9 }2 Li] 3Dy and show that dicarbollide ligands impose strong magnetic axiality on the central DyIII ion. The effective energy barrier (Ueff ) for the loss of magnetization can be varied by the substitution pattern on the dicarbollide. This finding is demonstrated by comparing complexes of nido-C2 B9 H11 2- and nido-[o-xylylene-C2 B9 H9 ]2- , which show a Ueff of 430(5) K and 804(7) K, respectively. The blocking temperature defined by the open hysteresis temperature of 3Dy reaches 6.8 K. Moreover, the linear complex [Dy(C2 B9 H11 )2 ]- is predicted to have comparable properties with the linear [Dy(CpMe3 )2 ]+ complex. As such, carboranyl ligands and their derivatives may provide a new type of organometallic ligand for high-performance single-molecule magnets.

All-polarization-maintaining (PM) fiber oscillator based on nonlinear amplifying loop mirror (NALM) modelocking has important applications for chirped pulse amplification systems. In this paper, we report an all-PM-fiberintegrated femtosecond chirped pulse amplification (CPA) system operating at 1030 nm, which consists of a NALM oscillator, an ytterbium-doped amplifier and a chirped volume Bragg grating (CVBG) compressor. The laser produces linearly polarized, linearly chirped pulses that can be recompressed down to 711 fs, corresponding to 95% compression efficiency. All-PM NALM fiber oscillator combined with CVBG compressor is a promising method for CPA system due to its extremely compact and robust architecture.

In order to reduce the ignition energy of the tantalum nitride film transducer, a new type of energy exchangers bridge area was designed in this paper, and it was fabricated by MEMS technology. The parameters of ignition voltage, ignition energy, as well as action time were tested. The experimental results showed that in terms of ignition voltage, ignition energy, and action time, the value of the energy exchangers element of the new bridge area was lower than the value of the energy exchangers element of the conventional bridge area. In addition, ignition performance can be reduced by many energy exchangers in the new bridge area.

Breakfast consumption is correlated with a range of positive outcomes, namely good academicperformance, appropriate nutrient intake and body mass index (BMI). However, many university studentshave the habits of skipping breakfast and consume an insufficient amount of nutrients. This study aimed todetermine the relationship between skipping breakfast and dietary intake with BMI among students of aprivate university in Shah Alam, Malaysia. A self-administered questionnaire was used in a cross-sectionalstudy of 200 students. The questionnaire asked about sociodemographic factors, dietary habits, and foodintake over 24 hours. SPSS and Nutritionist pro tools were used to analyse the data. Breakfast was skippedby 58% of students (60% of males and 56% females). Students' most common reason to skip breakfast is alack of time (n = 146; 73%). The majority of those who consumed more than 2500kcal per day wereoverweight. The results showed no significant association (p = 0.831) between breakfast skipping and BMI.There was no significant association (p > 0.05) between covariates (socio-demography, anthropometry,intakes of protein, carbohydrate, sodium, iron and vitamin C) with the BMI of students. However, there wasa significant association (p = 0.001) between dietary intake (calorie) and BMI. In conclusion, it is evidencedthat the dietary intake of these students influences their BMI status instead of the behaviour of skippingbreakfast. The importance of having breakfast should be emphasised among university students. Thestudents should prioritise their daily nutrient intake by taking regular breakfast

As a key subassembly of MEMS-based initiator, temperature is a decisive performance for Ni-Cr igniter. In order to get the transient heat response of Ni-Cr igniter, two different type of Ni-Cr igniters, including rectangle –shape type and V-shape type, were designed and fabricated on Pyrex7740 glass substrate. By the micro-sized infrared thermal technology, temperature distributions on surface of the igniter were measured under capacity charge excitations. Transient electro-thermal transfer models were presented and used to calculate the temperature distributions in the Ni-Cr igniters. By comparison, experimental values and simulation results deviated less than 5%, indicating the reliability and credibility of the simulation results. Rectangle-shape with smaller width at the half length has a more peak temperature, and the temperature at the center of the rectangle-shape is maximum. Two temperature peaks with same value in the V-shape Ni-Cr igniter appear near the two cross boundaries, and the V-shape igniter with less cross angle shows more temperature peak. It is of vital importance to guide the design of Ni-Cr igniter for initiating the next micro-sized explosives successfully.

We report on a compact, stable, all-fiberized narrow-linewidth (0.045 nm) pulsed laser source emitting laser beam with a wavelength of 266 nm, and tunable pulse width and repetition rate. The system is based on all-fiberized nanosecond amplifier architecture, which consists of Yb-doped fiber preamplifiers and a super-large-mode-area Yb-doped fiber power amplifier. The fiber amplifier with a core of 50 μm is used to raise the threshold of the stimulated Brillouin scattering (SBS) effect and to obtain high output power and single pulse energy. Using lithium triborate (LBO) crystal and beta-barium borate (BBO) crystal for realizing the second-harmonic generation (SHG) and fourth-harmonic generation (FHG), we achieve 17 μJ (1.73 W) and 0.66 μJ (66 mW), respectively, at wavelengths of 532 nm and 266 nm and a repetition rate of 100 kHz with pulse width of 4 ns. This source has great potential applications in fluorescence research and solar-blind ultraviolet optical communication.

Fire warning sensor capable of rapidly monitoring critical fire risk of combustible materials growingly plays a crucial role in reducing or avioding fire disaster under complicated environments. Unfortunately, to date the rational design of smart fire warning sensors that are reusable and weather-resistant remains a major challenge. Here, we report a facile and green strategy for fabricating biomimetic polyethylene glycol or polyvinyl pyrrolidone polymer decorated Ti3C2Tx MXene networks that possess exceptional flame resistance and sensitive fire cyclic warning performance. Novel fire warning sensors that were constructed based on the as-prepared inherently fire-retardant MXene networks exhibit ultrafast fire warning response and recovery time (~1.8 s and ~1.0 s), resistance switching behavior with >4 orders of magnitude, and stable fire cyclic warning capability for 100 cycles. Structural observation and analysis disclose that, upon flame attack, thermal pyrolysis of the polymer molecules facilitates the oxidation of MXene sheets to form a compact fish scale-like C/N dopped titania network, and meanwhile its electron excitation is thus activated to generate a sensitive resistance transition to trigger a rapid fire cyclic warning signal. More improtantly, the multifunctional MXene networks treated with silane modification not only endow combustible substrate with excellent super-hydrophobicity and outstanding flame resistance, but provide reusable and weather-resistant fire warning responses even after one-year outdoor exposure. Therefore, this work provides an innovative concept of advanced MXene composites and design of fire cyclic warning sensors for fire safety and prevention.

Dicarbollide ion, nido-C2B9H112- is isoelectronic with cyclopentadienyl. Here we make dysprosiacarboranes, namely [(C2B9H11)2Ln(THF)2][Na(THF)5] (Ln = Dy, 1Dy) and [(THF)3(μ-H)3Li]2[{η5-C6H4(CH2)2C2B9H9}Dy{η2:η5-C6H4(CH2)2C2B9H9}2Li] 3 and show that dicarbollide ligands impose strong magnetic axiality on the central Dy(III) ion. The effective energy barrier (Ueff) for loss of magnetisation can be varied by the substitution pattern on the dicarbollide. This is demonstrated by comparing complexes of nido-C2B9H112- and nido-[o-xylylene-C2B9H9]2- which show Ueff of 430(5) K and 804(7) K, respectively. The blocking temperature defined by the open hysteresis temperature of 3 reaches 6.8 K. Moreover, the linear complex [Dy(C2B9H11)2]- is predicted to have comparable SMM properties with linear [Dy(CpMe3)2]+ complex. As such, carboranyl ligands and its derivatives may open a new type of organometallic ligands for high-performance SMM design.

We report a dichlorido-bridged dinuclear dysprosium(III) single-molecule magnet [Dy(Cy2N)2(μ-Cl)(THF)]2 which shows an effective energy barrier for magnetization reversal (Ueff) of ca. 623 K. This is by far the largest Ueff barrier for any chlorido-bridged lanthanide single-molecule magnet. We observe two relaxation processes with near-identical temperature dependencies, one of which disappears upon magnetic dilution. We suspect that these two processes are the isolated and coupled relaxation processes.

The design criteria for single-molecule magnets (SMMs) of dysprosium(III) to show large thermal energy barriers to magnetic reversal have been established and proven, and the challenge to enhance their performance is understanding and control of vibrational modes that govern slow relaxation. We have prepared a new SMM, [Dy(L)2(py)5][BPh4] 1 (where HL = (S)-(-)-1-phenylethanol), which is based on the archetype [Dy(OtBu)2(py)5][BPh4] 2. Compounds 1 and 2 have similarly large energy barriers of Ueff = 1130(20) cm-1 and Ueff = 1250(10) cm-1, and yet 1 shows magnetic hysteresis at a far higher temperature of 22 K (cf. TH = 4 K for 2). Ab initio calculation of the spin dynamics show that substitution of the alkoxide ligand in fact enhances relaxation over the energy barrier for 1 over 2, in agreement with experiment, and that the higher temperature of magnetic hysteresis owes to reduced quantum tunnelling at low temperatures.

Two four-coordinate Dy(III) complexes, [LiTHF4][Dy(NPh2)4] (1) and DyLi(Ph3CO)3(NPh2)THF (2), with similar distorted tetrahedral geometries and a pure anionic coordination environment were synthesized under anaerobic conditions. Magnetic studies reveal that only 2 having a short Dy–O bond (2.07 A) shows slow magnetic relaxation behaviour under zero dc field. Quantitative analyses of energy-levels and eigenstates using the program PHI reveal that the ground state doublets for both the complexes are mixed with low-lying states, though complex 2 shows much higher purity of ground state doublets. This study presumably indicates that the spherically coordinated anions with evenly distributed charges are adverse to the enhancement of the axial magnetic anisotropy of the Dy(III) ions, while the strong Dy–O bond may break such a high symmetry and hence promote the axial magnetic anisotropy of the Dy(III) ions.

Objective To investigate the larvicidal activity, inhibition effect on development, histopathological alteration and morphological aberration induced by the extracts derived from seaweeds Bryopsis pennata ( B. pennata ) , Sargassum binderi ( S. binderi ) and Padina australis in Aedes aegypti ( Ae. aegypti ) larvae and to characterize the phytochemical components of the three seaweeds. Methods Larvicidal activity of the seaweeds towards the larvae of Ae. aegypti was determined according to WHO. The inhibition effect of seaweeds was assessed by determining the mortality, adult emergence rate, larval and pupa duration of the treated larvae. Histopathological effect on midgut epithelium of larvae and morphological aberration induced by the methanol extracts were examined. Phytochemical analysis was done to determine the presence of alkaloids, saponins, steroids and terpenoids in the seaweeds. Results Chloroform partition of B. pennata extract exhibited the strongest larvicidal activity (LC 50 = 82.55 μg/mL), followed by methanol extract of B. pennata (LC 50 = 160.07 μg/mL) and chloroform partition of S. binderi extract (LC 50 = 192.43 μg/mL). The methanol extract of S. binderi exhibited the strongest effect on prolongation of larval period (1.5-fold longer as compared to control) and resulted in strongest inhibition effect in adult emergence (98.67%). The histopathological study showed that larvae treated with seaweed extracts had cytopathological alteration of the midgut epithelium. The morphological observation revealed that the anal papillae and terminal spiracles of larvae were the common sites of aberrations. Conclusions The study provided information on various effects of seaweed extracts on Ae. aegypti . Further investigation on identifying the active compounds and their mechanisms of action is recommended.

We demonstrate an all-fiberized narrow-linewidth nanosecond amplifier with high peak power, tunable pulse width, and repetition rate. A fiber-coupled narrow-linewidth laser diode operating at 1064.1 nm is employed as the seed source, which is gain-switched to generate nanosecond pulses with tunable pulse widths of 1–200 ns and tunable repetition rates of 10 Hz–100 kHz. By utilizing a very-large-mode-area Yb-doped fiber with a core diameter of 50 μm in the power amplifier, thresholds of the stimulated Brillouin scattering at different pulse widths and repetition rates are increased. The maximum average power reaches 30.8 W at the pulse width of 4 ns and a repetition rate of 100 kHz, corresponding to an optical-to-optical conversion efficiency of ∼55.2%. Pulse energy and peak power are calculated to be 0.2 mJ and 50 kW, respectively, which are limited by stimulated Brillouin scattering. The 3-dB spectral linewidth remains around 0.05 nm during the power scaling process. The stimulated Brillouin scattering limited output powers at different pulse widths and repetition rates are investigated. Peak power of 47.5 kW (0.19 mJ) is obtained for the 4 ns pulses at a repetition rate of 50 kHz, which is nearly the same as that of 4 ns pulses at 100 kHz. When the pulse width of the seed source is increased to 8 ns, peak powers/pulse energies are decreased to 19.6 kW/0.11 mJ and 13.3 kW/0.08 mJ at repetition rates of 50 kHz and 100 kHz, respectively.

The ever-increasing threat from infectious diseases and the development of insecticide resistance in mosquito populations drive the global search for new natural insecticides. The aims of this study were to evaluate the mosquitocidal activity of the extracts of seaweed Bryopsis pennata against dengue vectors Aedes aegypti and Aedes albopictus, and determine the seaweed’s toxic effect on brine shrimp nauplii (as a non-target organism). In addition, the chemical compositions of the active larvicidal extract and fraction were analyzed by using liquid chromatography-mass spectrometry (LC-MS). Chloroform extract exhibited strong ovicidal activity (with LC50 values of 229.3 and 250.5 µg/mL) and larvicidal activity against Ae. aegypti and Ae. albopictus. The larvicidal potential of chloroform extract was further ascertained when its A7 fraction exhibited strong toxic effect against Ae. aegypti (LC50 = 4.7 µg/mL) and Ae. albopictus (LC50 = 5.3 µg/mL). LC-MS analysis of the chloroform extract gave a tentative identification of 13 compounds, Bis-(3-oxoundecyl) tetrasulfide was identified as the major compound in A7 fraction. Methanol extract showed strong repellent effect against female oviposition, along with weak adulticidal activity against mosquito and weak toxicity against brine shrimp nauplii. The mosquitocidal results of B. pennata suggest further investigation for the development of effective insecticide.

Despite the extensive work on anticancer drug discovery, the number of potent lead compounds that enter the preclinical and clinical trials thus far is still low due to the poor selectivity and understanding in pharmacodynamics. In view of the homology between zebrafish embryogenesis and carcinogenesis in human, zebrafish embryos can be used in the screening platform to elucidate the molecular targets of potential anticancer compounds. In the present study, the possible targets modulating the potential anticancer effects of selected brown seaweed-derived compounds (ie alginate, fucoidan, phloroglucinol, fucosterol, and fucoxanthin) were examined. Teratogenic effects induced by the compounds were observed after 72 hours post-fertilization. Fucoidan, phloroglucinol, and fucosterol were observed to significantly reduce the pigmentation of the zebrafish in a dose-dependent manner at low concentrations (fucoidan